30681920 has 28 divisors (see below), whose sum is σ = 73062084. Its totient is φ = 12272640.

The previous prime is 30681907. The next prime is 30681961. The reversal of 30681920 is 2918603.

It can be written as a sum of positive squares in 2 ways, for example, as 22886656 + 7795264 = 4784^2 + 2792^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47621 + ... + 48260.

Almost surely, 2^30681920 is an apocalyptic number.

It is an amenable number.

30681920 is an abundant number, since it is smaller than the sum of its proper divisors (42380164).

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

30681920 is an equidigital number, since it uses as much as digits as its factorization.

30681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95898 (or 95888 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 30681920 is about 5539.1262848937. The cubic root of 30681920 is about 313.0599496611.

The spelling of 30681920 in words is "thirty million, six hundred eighty-one thousand, nine hundred twenty".