21261054978982 has 32 divisors (see below), whose sum is σ = 39470458809600. Its totient is φ = 8363978150688.

The previous prime is 21261054978979. The next prime is 21261054978991. The reversal of 21261054978982 is 28987945016212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 326277432 + ... + 326342587.

It is an arithmetic number, because the mean of its divisors is an integer number (1233451837800).

Almost surely, 2^{21261054978982} is an apocalyptic number.

21261054978982 is a deficient number, since it is larger than the sum of its proper divisors (18209403830618).

21261054978982 is a wasteful number, since it uses less digits than its factorization.

21261054978982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652620220.

The product of its (nonzero) digits is 34836480, while the sum is 64.

The spelling of 21261054978982 in words is "twenty-one trillion, two hundred sixty-one billion, fifty-four million, nine hundred seventy-eight thousand, nine hundred eighty-two".