161515615 has 4 divisors (see below), whose sum is σ = 193818744. Its totient is φ = 129212488.

The previous prime is 161515609. The next prime is 161515631. The reversal of 161515615 is 516515161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161515615 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16151557 + ... + 16151566.

It is an arithmetic number, because the mean of its divisors is an integer number (48454686).

Almost surely, 2^161515615 is an apocalyptic number.

161515615 is a deficient number, since it is larger than the sum of its proper divisors (32303129).

161515615 is an equidigital number, since it uses as much as digits as its factorization.

161515615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32303128.

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

The square root of 161515615 is about 12708.8793762471. The cubic root of 161515615 is about 544.5923107635.

The spelling of 161515615 in words is "one hundred sixty-one million, five hundred fifteen thousand, six hundred fifteen".