21051551432 has 16 divisors (see below), whose sum is σ = 39473548800. Its totient is φ = 10525271760.

The previous prime is 21051551387. The next prime is 21051551447. The reversal of 21051551432 is 23415515012.

It is a junction number, because it is equal to n+sod(n) for n = 21051551395 and 21051551404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161669 + ... + 261227.

It is an arithmetic number, because the mean of its divisors is an integer number (2467096800).

Almost surely, 2^21051551432 is an apocalyptic number.

It is an amenable number.

21051551432 is a deficient number, since it is larger than the sum of its proper divisors (18421997368).

21051551432 is a wasteful number, since it uses less digits than its factorization.

21051551432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125996 (or 125992 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

The spelling of 21051551432 in words is "twenty-one billion, fifty-one million, five hundred fifty-one thousand, four hundred thirty-two".