21552131 has 2 divisors, whose sum is σ = 21552132. Its totient is φ = 21552130.

The previous prime is 21552119. The next prime is 21552143. The reversal of 21552131 is 13125512.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21552119) and next prime (21552143).

It is a cyclic number.

It is not a de Polignac number, because 21552131 - 2⁶ = 21552067 is a prime.

It is a super-2 number, since 2×21552131² = 928988701282322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21552031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776065 + 10776066.

It is an arithmetic number, because the mean of its divisors is an integer number (10776066).

Almost surely, 2^21552131 is an apocalyptic number.

21552131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552131 is an equidigital number, since it uses as much as digits as its factorization.

21552131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 300, while the sum is 20.

The square root of 21552131 is about 4642.4272746054. The cubic root of 21552131 is about 278.2894480233.

Adding to 21552131 its reverse (13125512), we get a palindrome (34677643).

The spelling of 21552131 in words is "twenty-one million, five hundred fifty-two thousand, one hundred thirty-one".