21199260626728 has 32 divisors (see below), whose sum is σ = 42319291046760. Its totient is φ = 9921005936640.

The previous prime is 21199260626693. The next prime is 21199260626767. The reversal of 21199260626728 is 82762606299112.

It can be written as a sum of positive squares in 4 ways, for example, as 19715926628644 + 1483333998084 = 4440262^2 + 1217922^2 .

It is a super-2 number, since 2×21199260626728² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 430574601 + ... + 430623832.

Almost surely, 2^{21199260626728} is an apocalyptic number.

It is an amenable number.

21199260626728 is a deficient number, since it is larger than the sum of its proper divisors (21120030420032).

21199260626728 is a wasteful number, since it uses less digits than its factorization.

21199260626728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861198637 (or 861198633 counting only the distinct ones).

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 21199260626728 in words is "twenty-one trillion, one hundred ninety-nine billion, two hundred sixty million, six hundred twenty-six thousand, seven hundred twenty-eight".