161620444 has 12 divisors (see below), whose sum is σ = 282927568. Its totient is φ = 80784000.

The previous prime is 161620421. The next prime is 161620447. The reversal of 161620444 is 444026161.

It is a super-2 number, since 2×161620444² = 52242335837514272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161620447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15724 + ... + 23884.

Almost surely, 2^161620444 is an apocalyptic number.

It is an amenable number.

161620444 is a deficient number, since it is larger than the sum of its proper divisors (121307124).

161620444 is a wasteful number, since it uses less digits than its factorization.

161620444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13116 (or 13114 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 161620444 is about 12713.0029497361. The cubic root of 161620444 is about 544.7101047838.

The spelling of 161620444 in words is "one hundred sixty-one million, six hundred twenty thousand, four hundred forty-four".