30725840 has 40 divisors (see below), whose sum is σ = 71781120. Its totient is φ = 12231296.

The previous prime is 30725839. The next prime is 30725857. The reversal of 30725840 is 4852703.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18317 + ... + 19923.

It is an arithmetic number, because the mean of its divisors is an integer number (1794528).

Almost surely, 2^30725840 is an apocalyptic number.

It is an amenable number.

30725840 is an abundant number, since it is smaller than the sum of its proper divisors (41055280).

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

30725840 is a wasteful number, since it uses less digits than its factorization.

30725840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859 (or 1853 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 30725840 is about 5543.0893913052. The cubic root of 30725840 is about 313.2092562400.

The spelling of 30725840 in words is "thirty million, seven hundred twenty-five thousand, eight hundred forty".