161611155 has 12 divisors (see below), whose sum is σ = 280126080. Its totient is φ = 86192592.

The previous prime is 161611147. The next prime is 161611159. The reversal of 161611155 is 551116161.

It is not a de Polignac number, because 161611155 - 2³ = 161611147 is a prime.

It is a super-2 number, since 2×161611155² = 52236330840868050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161611159) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1795635 + ... + 1795724.

It is an arithmetic number, because the mean of its divisors is an integer number (23343840).

Almost surely, 2^161611155 is an apocalyptic number.

161611155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161611155 is a deficient number, since it is larger than the sum of its proper divisors (118514925).

161611155 is a wasteful number, since it uses less digits than its factorization.

161611155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3591370 (or 3591367 counting only the distinct ones).

The product of its digits is 900, while the sum is 27.

The square root of 161611155 is about 12712.6376098747. The cubic root of 161611155 is about 544.6996689978.

The spelling of 161611155 in words is "one hundred sixty-one million, six hundred eleven thousand, one hundred fifty-five".