83981520 has 240 divisors, whose sum is σ = 339680640. Its totient is φ = 18164736.

The previous prime is 83981509. The next prime is 83981543. The reversal of 83981520 is 2518938.

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 95322 + ... + 96198.

It is an arithmetic number, because the mean of its divisors is an integer number (1415336).

Almost surely, 2^83981520 is an apocalyptic number.

83981520 is a gapful number since it is divisible by the number (80) 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 83981520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169840320).

83981520 is an abundant number, since it is smaller than the sum of its proper divisors (255699120).

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

83981520 is a wasteful number, since it uses less digits than its factorization.

83981520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 83981520 is about 9164.1431678035. The cubic root of 83981520 is about 437.9197951596.

The spelling of 83981520 in words is "eighty-three million, nine hundred eighty-one thousand, five hundred twenty".