30999978 has 24 divisors (see below), whose sum is σ = 68597568. Its totient is φ = 10113192.

The previous prime is 30999953. The next prime is 30999979. The reversal of 30999978 is 87999903.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (30999979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17476 + ... + 19167.

It is an arithmetic number, because the mean of its divisors is an integer number (2858232).

Almost surely, 2^30999978 is an apocalyptic number.

30999978 is an abundant number, since it is smaller than the sum of its proper divisors (37597590).

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

30999978 is a wasteful number, since it uses less digits than its factorization.

30999978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36698 (or 36695 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The square root of 30999978 is about 5567.7623871713. The cubic root of 30999978 is about 314.1379909269.

The spelling of 30999978 in words is "thirty million, nine hundred ninety-nine thousand, nine hundred seventy-eight".