21515004044131 has 4 divisors (see below), whose sum is σ = 23170004355232. Its totient is φ = 19860003733032.

The previous prime is 21515004044123. The next prime is 21515004044161. The reversal of 21515004044131 is 13144040051512.

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

It is a cyclic number.

It is not a de Polignac number, because 21515004044131 - 2³ = 21515004044123 is a prime.

It is a super-2 number, since 2×21515004044131² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21515004044093 and 21515004044102.

It is not an unprimeable number, because it can be changed into a prime (21515004044161) 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, 827500155531 + ... + 827500155556.

It is an arithmetic number, because the mean of its divisors is an integer number (5792501088808).

Almost surely, 2^{21515004044131} is an apocalyptic number.

21515004044131 is a deficient number, since it is larger than the sum of its proper divisors (1655000311101).

21515004044131 is a wasteful number, since it uses less digits than its factorization.

21515004044131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1655000311100.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 21515004044131 its reverse (13144040051512), we get a palindrome (34659044095643).

The spelling of 21515004044131 in words is "twenty-one trillion, five hundred fifteen billion, four million, forty-four thousand, one hundred thirty-one".