163991520 has 768 divisors, whose sum is σ = 783820800. Its totient is φ = 30965760.

The previous prime is 163991501. The next prime is 163991533. The reversal of 163991520 is 25199361.

163991520 = T₁₀₄ + T₁₀₅ + ... + T₉₉₄.

163991520 is a `hidden beast` number, since 1 + 639 + 9 + 15 + 2 + 0 = 666.

163991520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5654866 + ... + 5654894.

It is an arithmetic number, because the mean of its divisors is an integer number (1020600).

Almost surely, 2^163991520 is an apocalyptic number.

163991520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 163991520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391910400).

163991520 is an abundant number, since it is smaller than the sum of its proper divisors (619829280).

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

163991520 is a wasteful number, since it uses less digits than its factorization.

163991520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 163991520 is about 12805.9173822105. The cubic root of 163991520 is about 547.3609329662.

The spelling of 163991520 in words is "one hundred sixty-three million, nine hundred ninety-one thousand, five hundred twenty".