31305020 has 12 divisors (see below), whose sum is σ = 65740584. Its totient is φ = 12522000.

The previous prime is 31305019. The next prime is 31305023. The reversal of 31305020 is 2050313.

It is a junction number, because it is equal to n+sod(n) for n = 31304986 and 31305004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31305023) 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, 782606 + ... + 782645.

It is an arithmetic number, because the mean of its divisors is an integer number (5478382).

Almost surely, 2^31305020 is an apocalyptic number.

It is an amenable number.

31305020 is an abundant number, since it is smaller than the sum of its proper divisors (34435564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31305020 is a wasteful number, since it uses less digits than its factorization.

31305020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1565260 (or 1565258 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 14.

The square root of 31305020 is about 5595.0889179708. The cubic root of 31305020 is about 315.1650097081.

Adding to 31305020 its reverse (2050313), we get a palindrome (33355333).

The spelling of 31305020 in words is "thirty-one million, three hundred five thousand, twenty".