31420618 has 4 divisors (see below), whose sum is σ = 47130930. Its totient is φ = 15710308.

The previous prime is 31420603. The next prime is 31420619. The reversal of 31420618 is 81602413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81602413 = 23 ⋅3547931.

It can be written as a sum of positive squares in only one way, i.e., 18003049 + 13417569 = 4243^2 + 3663^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31420592 and 31420601.

It is not an unprimeable number, because it can be changed into a prime (31420619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7855153 + ... + 7855156.

Almost surely, 2^31420618 is an apocalyptic number.

31420618 is a deficient number, since it is larger than the sum of its proper divisors (15710312).

31420618 is a wasteful number, since it uses less digits than its factorization.

31420618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15710311.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 31420618 is about 5605.4097084870. The cubic root of 31420618 is about 315.5524629308.

The spelling of 31420618 in words is "thirty-one million, four hundred twenty thousand, six hundred eighteen".