161697906 has 12 divisors (see below), whose sum is σ = 350345502. Its totient is φ = 53899296.

The previous prime is 161697871. The next prime is 161697941. The reversal of 161697906 is 609796161.

It is an interprime number because it is at equal distance from previous prime (161697871) and next prime (161697941).

It can be written as a sum of positive squares in only one way, i.e., 95942025 + 65755881 = 9795^2 + 8109^2 .

It is a super-2 number, since 2×161697906² = 52292425609569672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4491591 + ... + 4491626.

Almost surely, 2^161697906 is an apocalyptic number.

161697906 is an abundant number, since it is smaller than the sum of its proper divisors (188647596).

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

161697906 is a wasteful number, since it uses less digits than its factorization.

161697906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8983225 (or 8983222 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The square root of 161697906 is about 12716.0491505813. The cubic root of 161697906 is about 544.7971143928.

The spelling of 161697906 in words is "one hundred sixty-one million, six hundred ninety-seven thousand, nine hundred six".