30811988 has 6 divisors (see below), whose sum is σ = 53920986. Its totient is φ = 15405992.

The previous prime is 30811981. The next prime is 30811993. The reversal of 30811988 is 88911803.

It can be written as a sum of positive squares in only one way, i.e., 30780304 + 31684 = 5548^2 + 178^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30811981) by changing a digit.

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 as a sum of consecutive naturals, namely, 3851495 + ... + 3851502.

It is an arithmetic number, because the mean of its divisors is an integer number (8986831).

Almost surely, 2^30811988 is an apocalyptic number.

It is an amenable number.

30811988 is a deficient number, since it is larger than the sum of its proper divisors (23108998).

30811988 is a wasteful number, since it uses less digits than its factorization.

30811988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7703001 (or 7702999 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 38.

The square root of 30811988 is about 5550.8547089615. The cubic root of 30811988 is about 313.5017046899.

The spelling of 30811988 in words is "thirty million, eight hundred eleven thousand, nine hundred eighty-eight".