21557151065101 has 4 divisors (see below), whose sum is σ = 21758619766752. Its totient is φ = 21355682363452.

The previous prime is 21557151065069. The next prime is 21557151065137. The reversal of 21557151065101 is 10156015175512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21557151065101 - 2⁵ = 21557151065069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21557151065171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100734350665 + ... + 100734350878.

It is an arithmetic number, because the mean of its divisors is an integer number (5439654941688).

Almost surely, 2^{21557151065101} is an apocalyptic number.

It is an amenable number.

21557151065101 is a deficient number, since it is larger than the sum of its proper divisors (201468701651).

21557151065101 is a wasteful number, since it uses less digits than its factorization.

21557151065101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201468701650.

The product of its (nonzero) digits is 52500, while the sum is 40.

The spelling of 21557151065101 in words is "twenty-one trillion, five hundred fifty-seven billion, one hundred fifty-one million, sixty-five thousand, one hundred one".