165151655515491 has 4 divisors (see below), whose sum is σ = 220202207353992. Its totient is φ = 110101103676992.

The previous prime is 165151655515477. The next prime is 165151655515493. The reversal of 165151655515491 is 194515556151561.

165151655515491 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 a cyclic number.

It is not a de Polignac number, because 165151655515491 - 2⁵ = 165151655515459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165151655515493) 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, 27525275919246 + ... + 27525275919251.

It is an arithmetic number, because the mean of its divisors is an integer number (55050551838498).

Almost surely, 2^{165151655515491} is an apocalyptic number.

165151655515491 is a deficient number, since it is larger than the sum of its proper divisors (55050551838501).

165151655515491 is an equidigital number, since it uses as much as digits as its factorization.

165151655515491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55050551838500.

The product of its digits is 20250000, while the sum is 60.

The spelling of 165151655515491 in words is "one hundred sixty-five trillion, one hundred fifty-one billion, six hundred fifty-five million, five hundred fifteen thousand, four hundred ninety-one".