165115651 has 4 divisors (see below), whose sum is σ = 169142904. Its totient is φ = 161088400.

The previous prime is 165115649. The next prime is 165115661. The reversal of 165115651 is 156511561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 156511561 = 79 ⋅1981159.

It is a cyclic number.

It is not a de Polignac number, because 165115651 - 2¹ = 165115649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165115661) 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, 2013565 + ... + 2013646.

It is an arithmetic number, because the mean of its divisors is an integer number (42285726).

Almost surely, 2^165115651 is an apocalyptic number.

165115651 is a deficient number, since it is larger than the sum of its proper divisors (4027253).

165115651 is an equidigital number, since it uses as much as digits as its factorization.

165115651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4027252.

The product of its digits is 4500, while the sum is 31.

The square root of 165115651 is about 12849.7334991820. The cubic root of 165115651 is about 548.6087714489.

The spelling of 165115651 in words is "one hundred sixty-five million, one hundred fifteen thousand, six hundred fifty-one".