161616404 has 6 divisors (see below), whose sum is σ = 282828714. Its totient is φ = 80808200.

The previous prime is 161616353. The next prime is 161616419. The reversal of 161616404 is 404616161.

It can be written as a sum of positive squares in only one way, i.e., 88548100 + 73068304 = 9410^2 + 8548^2 .

It is a super-2 number, since 2×161616404² = 52239724083782432, 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 as a sum of consecutive naturals, namely, 20202047 + ... + 20202054.

It is an arithmetic number, because the mean of its divisors is an integer number (47138119).

Almost surely, 2^161616404 is an apocalyptic number.

It is an amenable number.

161616404 is a deficient number, since it is larger than the sum of its proper divisors (121212310).

161616404 is a wasteful number, since it uses less digits than its factorization.

161616404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40404105 (or 40404103 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 161616404 is about 12712.8440563078. The cubic root of 161616404 is about 544.7055660693.

The spelling of 161616404 in words is "one hundred sixty-one million, six hundred sixteen thousand, four hundred four".