31385481 has 4 divisors (see below), whose sum is σ = 41847312. Its totient is φ = 20923652.

The previous prime is 31385461. The next prime is 31385489. The reversal of 31385481 is 18458313.

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: 18458313 = 3 ⋅6152771.

It is a cyclic number.

It is not a de Polignac number, because 31385481 - 2⁷ = 31385353 is a prime.

It is a super-2 number, since 2×31385481² = 1970096835202722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31385489) 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, 5230911 + ... + 5230916.

It is an arithmetic number, because the mean of its divisors is an integer number (10461828).

Almost surely, 2^31385481 is an apocalyptic number.

It is an amenable number.

31385481 is a deficient number, since it is larger than the sum of its proper divisors (10461831).

31385481 is a wasteful number, since it uses less digits than its factorization.

31385481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10461830.

The product of its digits is 11520, while the sum is 33.

The square root of 31385481 is about 5602.2746273277. The cubic root of 31385481 is about 315.4347938846.

The spelling of 31385481 in words is "thirty-one million, three hundred eighty-five thousand, four hundred eighty-one".