161315550 has 288 divisors, whose sum is σ = 526466304. Its totient is φ = 36288000.

The previous prime is 161315543. The next prime is 161315579. The reversal of 161315550 is 55513161.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2272015 + ... + 2272085.

It is an arithmetic number, because the mean of its divisors is an integer number (1828008).

Almost surely, 2^161315550 is an apocalyptic number.

161315550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161315550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263233152).

161315550 is an abundant number, since it is smaller than the sum of its proper divisors (365150754).

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

161315550 is a wasteful number, since it uses less digits than its factorization.

161315550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 161315550 is about 12701.0058656785. The cubic root of 161315550 is about 544.3673606295.

The spelling of 161315550 in words is "one hundred sixty-one million, three hundred fifteen thousand, five hundred fifty".