21256235504131 has 8 divisors (see below), whose sum is σ = 21830814748784. Its totient is φ = 20681660806560.

The previous prime is 21256235504123. The next prime is 21256235504143. The reversal of 21256235504131 is 13140553265212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21256235504131 - 2³ = 21256235504123 is a prime.

It is a super-2 number, since 2×21256235504131² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21256235504531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9722236 + ... + 11706166.

It is an arithmetic number, because the mean of its divisors is an integer number (2728851843598).

Almost surely, 2^{21256235504131} is an apocalyptic number.

21256235504131 is a deficient number, since it is larger than the sum of its proper divisors (574579244653).

21256235504131 is a wasteful number, since it uses less digits than its factorization.

21256235504131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2273541.

The product of its (nonzero) digits is 216000, while the sum is 40.

Adding to 21256235504131 its reverse (13140553265212), we get a palindrome (34396788769343).

The spelling of 21256235504131 in words is "twenty-one trillion, two hundred fifty-six billion, two hundred thirty-five million, five hundred four thousand, one hundred thirty-one".