161581465 has 16 divisors (see below), whose sum is σ = 197959680. Its totient is φ = 126584640.

The previous prime is 161581439. The next prime is 161581489. The reversal of 161581465 is 564185161.

It is not a de Polignac number, because 161581465 - 2¹³ = 161573273 is a prime.

It is a super-2 number, since 2×161581465² = 52217139663092450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48555 + ... + 51775.

It is an arithmetic number, because the mean of its divisors is an integer number (12372480).

Almost surely, 2^161581465 is an apocalyptic number.

It is an amenable number.

161581465 is a deficient number, since it is larger than the sum of its proper divisors (36378215).

161581465 is a wasteful number, since it uses less digits than its factorization.

161581465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3432.

The product of its digits is 28800, while the sum is 37.

The square root of 161581465 is about 12711.4698205990. The cubic root of 161581465 is about 544.6663108969. Note that the first 3 decimals are identical.

The spelling of 161581465 in words is "one hundred sixty-one million, five hundred eighty-one thousand, four hundred sixty-five".