161886640 has 40 divisors (see below), whose sum is σ = 377007120. Its totient is φ = 64647936.

The previous prime is 161886607. The next prime is 161886643. The reversal of 161886640 is 46688161.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 161886593 and 161886602.

It is not an unprimeable number, because it can be changed into a prime (161886643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62491 + ... + 65029.

It is an arithmetic number, because the mean of its divisors is an integer number (9425178).

Almost surely, 2^161886640 is an apocalyptic number.

161886640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161886640 is an abundant number, since it is smaller than the sum of its proper divisors (215120480).

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

161886640 is a wasteful number, since it uses less digits than its factorization.

161886640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3349 (or 3343 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 161886640 is about 12723.4680806767. The cubic root of 161886640 is about 545.0089946051.

The spelling of 161886640 in words is "one hundred sixty-one million, eight hundred eighty-six thousand, six hundred forty".