164991531 has 4 divisors (see below), whose sum is σ = 219988712. Its totient is φ = 109994352.

The previous prime is 164991529. The next prime is 164991557. The reversal of 164991531 is 135199461.

164991531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 164991531 - 2¹ = 164991529 is a prime.

It is a super-2 number, since 2×164991531² = 54444410603447922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 164991531.

It is not an unprimeable number, because it can be changed into a prime (164991571) 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, 27498586 + ... + 27498591.

It is an arithmetic number, because the mean of its divisors is an integer number (54997178).

Almost surely, 2^164991531 is an apocalyptic number.

164991531 is a deficient number, since it is larger than the sum of its proper divisors (54997181).

164991531 is an equidigital number, since it uses as much as digits as its factorization.

164991531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54997180.

The product of its digits is 29160, while the sum is 39.

The square root of 164991531 is about 12844.9029190570. The cubic root of 164991531 is about 548.4712710773.

The spelling of 164991531 in words is "one hundred sixty-four million, nine hundred ninety-one thousand, five hundred thirty-one".