21261964296898 has 16 divisors (see below), whose sum is σ = 34444663356600. Its totient is φ = 9785096194176.

The previous prime is 21261964296887. The next prime is 21261964296913. The reversal of 21261964296898 is 89869246916212.

It can be written as a sum of positive squares in 4 ways, for example, as 9466125963849 + 11795838333049 = 3076707^2 + 3434507^2 .

It is a super-2 number, since 2×21261964296898² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21261964296898.

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, 1171578115 + ... + 1171596262.

Almost surely, 2^{21261964296898} is an apocalyptic number.

21261964296898 is a deficient number, since it is larger than the sum of its proper divisors (13182699059702).

21261964296898 is a wasteful number, since it uses less digits than its factorization.

21261964296898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2343174741.

The product of its digits is 322486272, while the sum is 73.

The spelling of 21261964296898 in words is "twenty-one trillion, two hundred sixty-one billion, nine hundred sixty-four million, two hundred ninety-six thousand, eight hundred ninety-eight".