21290857268 has 24 divisors (see below), whose sum is σ = 38838048480. Its totient is φ = 10199876960.

The previous prime is 21290857223. The next prime is 21290857277. The reversal of 21290857268 is 86275809212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 685346 + ... + 715737.

It is an arithmetic number, because the mean of its divisors is an integer number (1618252020).

Almost surely, 2^21290857268 is an apocalyptic number.

It is an amenable number.

21290857268 is a deficient number, since it is larger than the sum of its proper divisors (17547191212).

21290857268 is a wasteful number, since it uses less digits than its factorization.

21290857268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1401247 (or 1401245 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 21290857268 in words is "twenty-one billion, two hundred ninety million, eight hundred fifty-seven thousand, two hundred sixty-eight".