23131444215511 has 4 divisors (see below), whose sum is σ = 23135256887512. Its totient is φ = 23127631543512.

The previous prime is 23131444215497. The next prime is 23131444215547. The reversal of 23131444215511 is 11551244413132.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23131444215511 is a prime.

It is a super-2 number, since 2×23131444215511² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23131444215571) 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, 1906326900 + ... + 1906339033.

It is an arithmetic number, because the mean of its divisors is an integer number (5783814221878).

Almost surely, 2^{23131444215511} is an apocalyptic number.

23131444215511 is a deficient number, since it is larger than the sum of its proper divisors (3812672001).

23131444215511 is an equidigital number, since it uses as much as digits as its factorization.

23131444215511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3812672000.

The product of its digits is 57600, while the sum is 37.

Adding to 23131444215511 its reverse (11551244413132), we get a palindrome (34682688628643).

The spelling of 23131444215511 in words is "twenty-three trillion, one hundred thirty-one billion, four hundred forty-four million, two hundred fifteen thousand, five hundred eleven".