161571553 has 16 divisors (see below), whose sum is σ = 200987136. Its totient is φ = 127607040.

The previous prime is 161571551. The next prime is 161571583. The reversal of 161571553 is 355175161.

It is not a de Polignac number, because 161571553 - 2¹ = 161571551 is a prime.

It is a super-2 number, since 2×161571553² = 52210733477663618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161571551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30801 + ... + 35662.

It is an arithmetic number, because the mean of its divisors is an integer number (12561696).

Almost surely, 2^161571553 is an apocalyptic number.

161571553 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

161571553 is a deficient number, since it is larger than the sum of its proper divisors (39415583).

161571553 is a wasteful number, since it uses less digits than its factorization.

161571553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66504.

The product of its digits is 15750, while the sum is 34.

The square root of 161571553 is about 12711.0799305173. The cubic root of 161571553 is about 544.6551733925.

The spelling of 161571553 in words is "one hundred sixty-one million, five hundred seventy-one thousand, five hundred fifty-three".