21373577155013 has 4 divisors (see below), whose sum is σ = 22110597056940. Its totient is φ = 20636557253088.

The previous prime is 21373577155009. The next prime is 21373577155027. The reversal of 21373577155013 is 31055177537312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14057947868449 + 7315629286564 = 3749393^2 + 2704742^2 .

It is a cyclic number.

It is not a de Polignac number, because 21373577155013 - 2² = 21373577155009 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 (21373577155813) 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, 368509950920 + ... + 368509950977.

It is an arithmetic number, because the mean of its divisors is an integer number (5527649264235).

Almost surely, 2^{21373577155013} is an apocalyptic number.

It is an amenable number.

21373577155013 is a deficient number, since it is larger than the sum of its proper divisors (737019901927).

21373577155013 is an equidigital number, since it uses as much as digits as its factorization.

21373577155013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737019901926.

The product of its (nonzero) digits is 2315250, while the sum is 50.

The spelling of 21373577155013 in words is "twenty-one trillion, three hundred seventy-three billion, five hundred seventy-seven million, one hundred fifty-five thousand, thirteen".