188221531 has 2 divisors, whose sum is σ = 188221532. Its totient is φ = 188221530.

The previous prime is 188221519. The next prime is 188221541. The reversal of 188221531 is 135122881.

It is a strong prime.

It is an emirp because it is prime and its reverse (135122881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 188221531 - 2⁵ = 188221499 is a prime.

It is a super-2 number, since 2×188221531² = 70854689463967922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 188221493 and 188221502.

It is not a weakly prime, because it can be changed into another prime (188221541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94110765 + 94110766.

It is an arithmetic number, because the mean of its divisors is an integer number (94110766).

Almost surely, 2^188221531 is an apocalyptic number.

188221531 is a deficient number, since it is larger than the sum of its proper divisors (1).

188221531 is an equidigital number, since it uses as much as digits as its factorization.

188221531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3840, while the sum is 31.

The square root of 188221531 is about 13719.3852267512. The cubic root of 188221531 is about 573.0903564868.

The spelling of 188221531 in words is "one hundred eighty-eight million, two hundred twenty-one thousand, five hundred thirty-one".