161601515 has 16 divisors (see below), whose sum is σ = 197920800. Its totient is φ = 126643200.

The previous prime is 161601511. The next prime is 161601599. The reversal of 161601515 is 515106161.

It is not a de Polignac number, because 161601515 - 2² = 161601511 is a prime.

It is a super-2 number, since 2×161601515² = 52230099300590450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161601511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47336 + ... + 50634.

It is an arithmetic number, because the mean of its divisors is an integer number (12370050).

Almost surely, 2^161601515 is an apocalyptic number.

161601515 is a deficient number, since it is larger than the sum of its proper divisors (36319285).

161601515 is a wasteful number, since it uses less digits than its factorization.

161601515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3502.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 161601515 is about 12712.2584539491. The cubic root of 161601515 is about 544.6888384558.

Adding to 161601515 its reverse (515106161), we get a palindrome (676707676).

The spelling of 161601515 in words is "one hundred sixty-one million, six hundred one thousand, five hundred fifteen".