30987945 has 12 divisors (see below), whose sum is σ = 53712516. Its totient is φ = 16526880.

The previous prime is 30987871. The next prime is 30987953. The reversal of 30987945 is 54978903.

It can be written as a sum of positive squares in 2 ways, for example, as 7601049 + 23386896 = 2757^2 + 4836^2 .

It is not a de Polignac number, because 30987945 - 2¹⁴ = 30971561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 688621 = 30987945 / (3 + 0 + 9 + 8 + 7 + 9 + 4 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 30987945.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 344266 + ... + 344355.

It is an arithmetic number, because the mean of its divisors is an integer number (4476043).

Almost surely, 2^30987945 is an apocalyptic number.

It is an amenable number.

30987945 is a deficient number, since it is larger than the sum of its proper divisors (22724571).

30987945 is a wasteful number, since it uses less digits than its factorization.

30987945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688632 (or 688629 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 30987945 is about 5566.6816866065. The cubic root of 30987945 is about 314.0973402353.

The spelling of 30987945 in words is "thirty million, nine hundred eighty-seven thousand, nine hundred forty-five".