990139860 has 72 divisors (see below), whose sum is σ = 3008861856. Its totient is φ = 263559360.

The previous prime is 990139849. The next prime is 990139867. The reversal of 990139860 is 68931099.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990139867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 100975 + ... + 110345.

It is an arithmetic number, because the mean of its divisors is an integer number (41789748).

Almost surely, 2^990139860 is an apocalyptic number.

990139860 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

990139860 is an abundant number, since it is smaller than the sum of its proper divisors (2018721996).

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

990139860 is a wasteful number, since it uses less digits than its factorization.

990139860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9973 (or 9968 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 990139860 is about 31466.4878879102. The cubic root of 990139860 is about 996.7024246159.

The spelling of 990139860 in words is "nine hundred ninety million, one hundred thirty-nine thousand, eight hundred sixty".