30905856 has 120 divisors (see below), whose sum is σ = 94156920. Its totient is φ = 9732096.

The previous prime is 30905843. The next prime is 30905867. The reversal of 30905856 is 65850903.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 30905856.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87376 + ... + 87728.

It is an arithmetic number, because the mean of its divisors is an integer number (784641).

Almost surely, 2^30905856 is an apocalyptic number.

30905856 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30905856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47078460).

30905856 is an abundant number, since it is smaller than the sum of its proper divisors (63251064).

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

30905856 is a wasteful number, since it uses less digits than its factorization.

30905856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 30905856 is about 5559.3035535038. The cubic root of 30905856 is about 313.8197404796.

The spelling of 30905856 in words is "thirty million, nine hundred five thousand, eight hundred fifty-six".