21255535160645 has 32 divisors (see below), whose sum is σ = 27669913528320. Its totient is φ = 15611467253760.

The previous prime is 21255535160641. The next prime is 21255535160659. The reversal of 21255535160645 is 54606153555212.

It is not a de Polignac number, because 21255535160645 - 2² = 21255535160641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21255535160593 and 21255535160602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255535160641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22819724 + ... + 23732906.

It is an arithmetic number, because the mean of its divisors is an integer number (864684797760).

Almost surely, 2^{21255535160645} is an apocalyptic number.

It is an amenable number.

21255535160645 is a deficient number, since it is larger than the sum of its proper divisors (6414378367675).

21255535160645 is a wasteful number, since it uses less digits than its factorization.

21255535160645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919925.

The product of its (nonzero) digits is 5400000, while the sum is 50.

The spelling of 21255535160645 in words is "twenty-one trillion, two hundred fifty-five billion, five hundred thirty-five million, one hundred sixty thousand, six hundred forty-five".