31203420 has 96 divisors (see below), whose sum is σ = 91929600. Its totient is φ = 7897344.

The previous prime is 31203409. The next prime is 31203427. The reversal of 31203420 is 2430213.

31203420 = 390² + 391² + ... + 534².

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31203420.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31203427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137347 + ... + 137573.

It is an arithmetic number, because the mean of its divisors is an integer number (957600).

Almost surely, 2^31203420 is an apocalyptic number.

31203420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31203420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45964800).

31203420 is an abundant number, since it is smaller than the sum of its proper divisors (60726180).

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

31203420 is a wasteful number, since it uses less digits than its factorization.

31203420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 31203420 is about 5586.0021482273. The cubic root of 31203420 is about 314.8236856589.

Adding to 31203420 its reverse (2430213), we get a palindrome (33633633).

The spelling of 31203420 in words is "thirty-one million, two hundred three thousand, four hundred twenty".