30978431 has 4 divisors (see below), whose sum is σ = 33794664. Its totient is φ = 28162200.

The previous prime is 30978427. The next prime is 30978439. The reversal of 30978431 is 13487903.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 30978431 - 2² = 30978427 is a prime.

It is a super-2 number, since 2×30978431² = 1919326374443522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 30978391 and 30978400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30978439) 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, 1408100 + ... + 1408121.

It is an arithmetic number, because the mean of its divisors is an integer number (8448666).

Almost surely, 2^30978431 is an apocalyptic number.

30978431 is a deficient number, since it is larger than the sum of its proper divisors (2816233).

30978431 is a wasteful number, since it uses less digits than its factorization.

30978431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2816232.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 30978431 is about 5565.8270724125. The cubic root of 30978431 is about 314.0651919491.

The spelling of 30978431 in words is "thirty million, nine hundred seventy-eight thousand, four hundred thirty-one".