21523432104 has 80 divisors (see below), whose sum is σ = 63458498400. Its totient is φ = 6796869408.

The previous prime is 21523432093. The next prime is 21523432111. The reversal of 21523432104 is 40123432512.

21523432104 is a `hidden beast` number, since 2 + 1 + 523 + 4 + 32 + 104 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 861772 + ... + 886395.

It is an arithmetic number, because the mean of its divisors is an integer number (793231230).

Almost surely, 2^21523432104 is an apocalyptic number.

21523432104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21523432104 is an abundant number, since it is smaller than the sum of its proper divisors (41935066296).

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

21523432104 is a wasteful number, since it uses less digits than its factorization.

21523432104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748204 (or 1748191 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21523432104 its reverse (40123432512), we get a palindrome (61646864616).

The spelling of 21523432104 in words is "twenty-one billion, five hundred twenty-three million, four hundred thirty-two thousand, one hundred four".