161551722 has 16 divisors (see below), whose sum is σ = 326303712. Its totient is φ = 53317200.

The previous prime is 161551669. The next prime is 161551763. The reversal of 161551722 is 227155161.

It is a self number, because there is not a number n which added to its sum of digits gives 161551722.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132688 + ... + 133899.

It is an arithmetic number, because the mean of its divisors is an integer number (20393982).

Almost surely, 2^161551722 is an apocalyptic number.

161551722 is an abundant number, since it is smaller than the sum of its proper divisors (164751990).

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

161551722 is a wasteful number, since it uses less digits than its factorization.

161551722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266693.

The product of its digits is 4200, while the sum is 30.

The square root of 161551722 is about 12710.2998391069. The cubic root of 161551722 is about 544.6328891506.

The spelling of 161551722 in words is "one hundred sixty-one million, five hundred fifty-one thousand, seven hundred twenty-two".