21203691056 has 40 divisors (see below), whose sum is σ = 41680573344. Its totient is φ = 10447557120.

The previous prime is 21203691043. The next prime is 21203691071. The reversal of 21203691056 is 65019630212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3897170 + ... + 3902606.

Almost surely, 2^21203691056 is an apocalyptic number.

It is an amenable number.

21203691056 is a deficient number, since it is larger than the sum of its proper divisors (20476882288).

21203691056 is a wasteful number, since it uses less digits than its factorization.

21203691056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8949 (or 8943 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The spelling of 21203691056 in words is "twenty-one billion, two hundred three million, six hundred ninety-one thousand, fifty-six".