21515010131305 has 4 divisors (see below), whose sum is σ = 25818012157572. Its totient is φ = 17212008105040.

The previous prime is 21515010131203. The next prime is 21515010131393. The reversal of 21515010131305 is 50313101051512.

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 6784581906729 + 14730428224576 = 2604723^2 + 3838024^2 .

It is not a de Polignac number, because 21515010131305 - 2³⁵ = 21480650392937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2151501013126 + ... + 2151501013135.

It is an arithmetic number, because the mean of its divisors is an integer number (6454503039393).

Almost surely, 2^{21515010131305} is an apocalyptic number.

It is an amenable number.

21515010131305 is a deficient number, since it is larger than the sum of its proper divisors (4303002026267).

21515010131305 is an equidigital number, since it uses as much as digits as its factorization.

21515010131305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4303002026266.

The product of its (nonzero) digits is 2250, while the sum is 28.

Adding to 21515010131305 its reverse (50313101051512), we get a palindrome (71828111182817).

The spelling of 21515010131305 in words is "twenty-one trillion, five hundred fifteen billion, ten million, one hundred thirty-one thousand, three hundred five".