21145190400 has 432 divisors, whose sum is σ = 78013756800. Its totient is φ = 5615124480.

The previous prime is 21145190389. The next prime is 21145190467. The reversal of 21145190400 is 409154112.

21145190400 is a `hidden beast` number, since 211 + 45 + 1 + 9 + 0 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88473481 + ... + 88473719.

It is an arithmetic number, because the mean of its divisors is an integer number (180587400).

Almost surely, 2^21145190400 is an apocalyptic number.

21145190400 is a gapful number since it is divisible by the number (20) 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 21145190400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39006878400).

21145190400 is an abundant number, since it is smaller than the sum of its proper divisors (56868566400).

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

21145190400 is an frugal number, since it uses more digits than its factorization.

21145190400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21145190400 in words is "twenty-one billion, one hundred forty-five million, one hundred ninety thousand, four hundred".