21603155212765 has 64 divisors (see below), whose sum is σ = 31539812451840. Its totient is φ = 13866889789440.

The previous prime is 21603155212757. The next prime is 21603155212777. The reversal of 21603155212765 is 56721255130612.

It is not a de Polignac number, because 21603155212765 - 2³ = 21603155212757 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 94798810 + ... + 95026420.

It is an arithmetic number, because the mean of its divisors is an integer number (492809569560).

Almost surely, 2^{21603155212765} is an apocalyptic number.

It is an amenable number.

21603155212765 is a deficient number, since it is larger than the sum of its proper divisors (9936657239075).

21603155212765 is a wasteful number, since it uses less digits than its factorization.

21603155212765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228502.

The product of its (nonzero) digits is 756000, while the sum is 46.

The spelling of 21603155212765 in words is "twenty-one trillion, six hundred three billion, one hundred fifty-five million, two hundred twelve thousand, seven hundred sixty-five".