21261011656612 has 48 divisors (see below), whose sum is σ = 45795739635072. Its totient is φ = 8410436951040.

The previous prime is 21261011656603. The next prime is 21261011656631. The reversal of 21261011656612 is 21665611016212.

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, 4227063 + ... + 7771105.

It is an arithmetic number, because the mean of its divisors is an integer number (954077909064).

Almost surely, 2^{21261011656612} is an apocalyptic number.

It is an amenable number.

21261011656612 is an abundant number, since it is smaller than the sum of its proper divisors (24534727978460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21261011656612 is a wasteful number, since it uses less digits than its factorization.

21261011656612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3560548 (or 3560546 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 21261011656612 in words is "twenty-one trillion, two hundred sixty-one billion, eleven million, six hundred fifty-six thousand, six hundred twelve".