161631660 has 48 divisors (see below), whose sum is σ = 453150432. Its totient is φ = 43046400.

The previous prime is 161631653. The next prime is 161631667. The reversal of 161631660 is 66136161.

161631660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (161631653) and next prime (161631667).

It is a super-2 number, since 2×161631660² = 52249587028711200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (161631667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69720 + ... + 72000.

It is an arithmetic number, because the mean of its divisors is an integer number (9440634).

Almost surely, 2^161631660 is an apocalyptic number.

161631660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161631660 is an abundant number, since it is smaller than the sum of its proper divisors (291518772).

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

161631660 is a wasteful number, since it uses less digits than its factorization.

161631660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3474 (or 3472 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 161631660 is about 12713.4440652405. Note that the first 3 decimals coincide. The cubic root of 161631660 is about 544.7227049373.

The spelling of 161631660 in words is "one hundred sixty-one million, six hundred thirty-one thousand, six hundred sixty".