165537399 has 8 divisors (see below), whose sum is σ = 220776192. Its totient is φ = 110328440.

The previous prime is 165537389. The next prime is 165537439. The reversal of 165537399 is 993735561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165537399 - 2⁷ = 165537271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165537389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16354 + ... + 24464.

It is an arithmetic number, because the mean of its divisors is an integer number (27597024).

Almost surely, 2^165537399 is an apocalyptic number.

165537399 is a deficient number, since it is larger than the sum of its proper divisors (55238793).

165537399 is an equidigital number, since it uses as much as digits as its factorization.

165537399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14917.

The product of its digits is 765450, while the sum is 48.

The square root of 165537399 is about 12866.1338015738. The cubic root of 165537399 is about 549.0754704625.

The spelling of 165537399 in words is "one hundred sixty-five million, five hundred thirty-seven thousand, three hundred ninety-nine".