216257131 has 2 divisors, whose sum is σ = 216257132. Its totient is φ = 216257130.

The previous prime is 216257123. The next prime is 216257141. The reversal of 216257131 is 131752612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216257131 - 2³ = 216257123 is a prime.

It is a super-2 number, since 2×216257131² = 93534293416702322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216257131.

It is not a weakly prime, because it can be changed into another prime (216257141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108128565 + 108128566.

It is an arithmetic number, because the mean of its divisors is an integer number (108128566).

Almost surely, 2^216257131 is an apocalyptic number.

216257131 is a deficient number, since it is larger than the sum of its proper divisors (1).

216257131 is an equidigital number, since it uses as much as digits as its factorization.

216257131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 28.

The square root of 216257131 is about 14705.6836291279. The cubic root of 216257131 is about 600.2379898482.

The spelling of 216257131 in words is "two hundred sixteen million, two hundred fifty-seven thousand, one hundred thirty-one".