21751038516 has 24 divisors (see below), whose sum is σ = 50775522784. Its totient is φ = 7247046240.

The previous prime is 21751038497. The next prime is 21751038539. The reversal of 21751038516 is 61583015712.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 384955 + ... + 437826.

Almost surely, 2^21751038516 is an apocalyptic number.

It is an amenable number.

21751038516 is an abundant number, since it is smaller than the sum of its proper divisors (29024484268).

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

21751038516 is a wasteful number, since it uses less digits than its factorization.

21751038516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824991 (or 824989 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 39.

The spelling of 21751038516 in words is "twenty-one billion, seven hundred fifty-one million, thirty-eight thousand, five hundred sixteen".