161590420 has 12 divisors (see below), whose sum is σ = 339339924. Its totient is φ = 64636160.

The previous prime is 161590397. The next prime is 161590463. The reversal of 161590420 is 24095161.

It can be written as a sum of positive squares in 2 ways, for example, as 122677776 + 38912644 = 11076^2 + 6238^2 .

It is a super-2 number, since 2×161590420² = 52222927671552800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4039741 + ... + 4039780.

It is an arithmetic number, because the mean of its divisors is an integer number (28278327).

Almost surely, 2^161590420 is an apocalyptic number.

161590420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161590420 is an abundant number, since it is smaller than the sum of its proper divisors (177749504).

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

161590420 is a wasteful number, since it uses less digits than its factorization.

161590420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8079530 (or 8079528 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 161590420 is about 12711.8220566526. The cubic root of 161590420 is about 544.6763726878.

It can be divided in two parts, 16 and 1590420, that added together give a triangular number (1590436 = T₁₇₈₃).

The spelling of 161590420 in words is "one hundred sixty-one million, five hundred ninety thousand, four hundred twenty".