21257286328 has 16 divisors (see below), whose sum is σ = 40784329080. Its totient is φ = 10381465248.

The previous prime is 21257286313. The next prime is 21257286331. The reversal of 21257286328 is 82368275212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30896875 + ... + 30897562.

Almost surely, 2^21257286328 is an apocalyptic number.

It is an amenable number.

21257286328 is a deficient number, since it is larger than the sum of its proper divisors (19527042752).

21257286328 is a wasteful number, since it uses less digits than its factorization.

21257286328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61794486 (or 61794482 counting only the distinct ones).

The product of its digits is 645120, while the sum is 46.

The spelling of 21257286328 in words is "twenty-one billion, two hundred fifty-seven million, two hundred eighty-six thousand, three hundred twenty-eight".