165772649 has 4 divisors (see below), whose sum is σ = 189454464. Its totient is φ = 142090836.

The previous prime is 165772631. The next prime is 165772667. The reversal of 165772649 is 946277561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 946277561 = 419 ⋅2258419.

It is an interprime number because it is at equal distance from previous prime (165772631) and next prime (165772667).

It is a cyclic number.

It is not a de Polignac number, because 165772649 - 2²⁰ = 164724073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165772249) 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, 11840897 + ... + 11840910.

It is an arithmetic number, because the mean of its divisors is an integer number (47363616).

Almost surely, 2^165772649 is an apocalyptic number.

It is an amenable number.

165772649 is a deficient number, since it is larger than the sum of its proper divisors (23681815).

165772649 is an equidigital number, since it uses as much as digits as its factorization.

165772649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23681814.

The product of its digits is 635040, while the sum is 47.

The square root of 165772649 is about 12875.2727738095. The cubic root of 165772649 is about 549.3354497066.

The spelling of 165772649 in words is "one hundred sixty-five million, seven hundred seventy-two thousand, six hundred forty-nine".