30990971 has 4 divisors (see below), whose sum is σ = 33808344. Its totient is φ = 28173600.

The previous prime is 30990961. The next prime is 30990997. The reversal of 30990971 is 17909903.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17909903 = 11 ⋅1628173.

It is a cyclic number.

It is not a de Polignac number, because 30990971 - 2¹⁸ = 30728827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30990931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1408670 + ... + 1408691.

It is an arithmetic number, because the mean of its divisors is an integer number (8452086).

Almost surely, 2^30990971 is an apocalyptic number.

30990971 is a deficient number, since it is larger than the sum of its proper divisors (2817373).

30990971 is a wasteful number, since it uses less digits than its factorization.

30990971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2817372.

The product of its (nonzero) digits is 15309, while the sum is 38.

The square root of 30990971 is about 5566.9534756454. The cubic root of 30990971 is about 314.1075638627.

The spelling of 30990971 in words is "thirty million, nine hundred ninety thousand, nine hundred seventy-one".