161555508 has 36 divisors (see below), whose sum is σ = 421552768. Its totient is φ = 52114320.

The previous prime is 161555507. The next prime is 161555509. The reversal of 161555508 is 805555161.

It is an interprime number because it is at equal distance from previous prime (161555507) and next prime (161555509).

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×161555508² = 52200364330276128, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161555503) 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, 71266 + ... + 73497.

Almost surely, 2^161555508 is an apocalyptic number.

161555508 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

161555508 is an abundant number, since it is smaller than the sum of its proper divisors (259997260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161555508 is a wasteful number, since it uses less digits than its factorization.

161555508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144804 (or 144799 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 36.

The square root of 161555508 is about 12710.4487725650. The cubic root of 161555508 is about 544.6371436478.

The spelling of 161555508 in words is "one hundred sixty-one million, five hundred fifty-five thousand, five hundred eight".