21152123131 has 16 divisors (see below), whose sum is σ = 21890663424. Its totient is φ = 20426255104.

The previous prime is 21152123107. The next prime is 21152123189. The reversal of 21152123131 is 13132125112.

It is a cyclic number.

It is not a de Polignac number, because 21152123131 - 2¹¹ = 21152121083 is a prime.

It is a super-2 number, since 2×21152123131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21152123101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3457131 + ... + 3463243.

It is an arithmetic number, because the mean of its divisors is an integer number (1368166464).

Almost surely, 2^21152123131 is an apocalyptic number.

21152123131 is a deficient number, since it is larger than the sum of its proper divisors (738540293).

21152123131 is an equidigital number, since it uses as much as digits as its factorization.

21152123131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7130.

The product of its digits is 360, while the sum is 22.

Adding to 21152123131 its reverse (13132125112), we get a palindrome (34284248243).

The spelling of 21152123131 in words is "twenty-one billion, one hundred fifty-two million, one hundred twenty-three thousand, one hundred thirty-one".