30471981 has 4 divisors (see below), whose sum is σ = 40629312. Its totient is φ = 20314652.

The previous prime is 30471967. The next prime is 30471983. The reversal of 30471981 is 18917403.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18917403 = 3 ⋅6305801.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30471981 is a prime.

It is a super-2 number, since 2×30471981² = 1857083252128722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30471983) 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, 5078661 + ... + 5078666.

It is an arithmetic number, because the mean of its divisors is an integer number (10157328).

Almost surely, 2^30471981 is an apocalyptic number.

It is an amenable number.

30471981 is a deficient number, since it is larger than the sum of its proper divisors (10157331).

30471981 is a wasteful number, since it uses less digits than its factorization.

30471981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10157330.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 30471981 is about 5520.1432046642. The cubic root of 30471981 is about 312.3442842345.

The spelling of 30471981 in words is "thirty million, four hundred seventy-one thousand, nine hundred eighty-one".