161616215 has 4 divisors (see below), whose sum is σ = 193939464. Its totient is φ = 129292968.

The previous prime is 161616211. The next prime is 161616269. The reversal of 161616215 is 512616161.

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 161616215 - 2² = 161616211 is a prime.

It is a super-2 number, since 2×161616215² = 52239601901852450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161616211) 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, 16161617 + ... + 16161626.

It is an arithmetic number, because the mean of its divisors is an integer number (48484866).

Almost surely, 2^161616215 is an apocalyptic number.

161616215 is a deficient number, since it is larger than the sum of its proper divisors (32323249).

161616215 is an equidigital number, since it uses as much as digits as its factorization.

161616215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32323248.

The product of its digits is 2160, while the sum is 29.

The square root of 161616215 is about 12712.8366228785. The cubic root of 161616215 is about 544.7053537365.

The spelling of 161616215 in words is "one hundred sixty-one million, six hundred sixteen thousand, two hundred fifteen".