163981980 has 36 divisors (see below), whose sum is σ = 497412552. Its totient is φ = 43728480.

The previous prime is 163981957. The next prime is 163981991. The reversal of 163981980 is 89189361.

163981980 is a `hidden beast` number, since 1 + 639 + 8 + 1 + 9 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 455326 + ... + 455685.

Almost surely, 2^163981980 is an apocalyptic number.

163981980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

163981980 is an abundant number, since it is smaller than the sum of its proper divisors (333430572).

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

163981980 is a wasteful number, since it uses less digits than its factorization.

163981980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911026 (or 911021 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 163981980 is about 12805.5448927408. The cubic root of 163981980 is about 547.3503187495.

The spelling of 163981980 in words is "one hundred sixty-three million, nine hundred eighty-one thousand, nine hundred eighty".