21400171398144 has 1408 divisors, whose sum is σ = 81422624870400. Its totient is φ = 5391014952960.

The previous prime is 21400171398131. The next prime is 21400171398161. The reversal of 21400171398144 is 44189317100412.

21400171398144 is a `hidden beast` number, since 2 + 1 + 400 + 1 + 7 + 13 + 98 + 144 = 666.

It is a tau number, because it is divible by the number of its divisors (1408).

It is a self number, because there is not a number n which added to its sum of digits gives 21400171398144.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 14372176152 + ... + 14372177640.

It is an arithmetic number, because the mean of its divisors is an integer number (57828568800).

Almost surely, 2^{21400171398144} is an apocalyptic number.

21400171398144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21400171398144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40711312435200).

21400171398144 is an abundant number, since it is smaller than the sum of its proper divisors (60022453472256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21400171398144 is a wasteful number, since it uses less digits than its factorization.

21400171398144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736 (or 1712 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

Adding to 21400171398144 its reverse (44189317100412), we get a palindrome (65589488498556).

It can be divided in two parts, 2140017 and 1398144, that added together give a square (3538161 = 1881²).

The spelling of 21400171398144 in words is "twenty-one trillion, four hundred billion, one hundred seventy-one million, three hundred ninety-eight thousand, one hundred forty-four".