21023420332144 has 20 divisors (see below), whose sum is σ = 42046840665280. Its totient is φ = 10172622741120.

The previous prime is 21023420332091. The next prime is 21023420332147. The reversal of 21023420332144 is 44123302432012.

21023420332144 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023420332147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21192963549 + ... + 21192964540.

It is an arithmetic number, because the mean of its divisors is an integer number (2102342033264).

Almost surely, 2^{21023420332144} is an apocalyptic number.

It is an amenable number.

21023420332144 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21023420332144 is a wasteful number, since it uses less digits than its factorization.

21023420332144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42385928128 (or 42385928122 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 31.

Adding to 21023420332144 its reverse (44123302432012), we get a palindrome (65146722764156).

The spelling of 21023420332144 in words is "twenty-one trillion, twenty-three billion, four hundred twenty million, three hundred thirty-two thousand, one hundred forty-four".