30999980 has 24 divisors (see below), whose sum is σ = 71018640. Its totient is φ = 11272640.

The previous prime is 30999979. The next prime is 30999989. The reversal of 30999980 is 8999903.

30999980 = 1965² + 1966² + ... + 1972².

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (30999989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70235 + ... + 70674.

It is an arithmetic number, because the mean of its divisors is an integer number (2959110).

Almost surely, 2^30999980 is an apocalyptic number.

It is an amenable number.

30999980 is an abundant number, since it is smaller than the sum of its proper divisors (40018660).

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

30999980 is a wasteful number, since it uses less digits than its factorization.

30999980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140929 (or 140927 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 47.

The square root of 30999980 is about 5567.7625667767. The cubic root of 30999980 is about 314.1379976826.

The spelling of 30999980 in words is "thirty million, nine hundred ninety-nine thousand, nine hundred eighty".