31122420 has 48 divisors (see below), whose sum is σ = 99593088. Its totient is φ = 7113600.

The previous prime is 31122409. The next prime is 31122449. The reversal of 31122420 is 2422113.

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 31122420.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36631 + ... + 37470.

It is an arithmetic number, because the mean of its divisors is an integer number (2074856).

Almost surely, 2^31122420 is an apocalyptic number.

31122420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31122420 is an abundant number, since it is smaller than the sum of its proper divisors (68470668).

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

31122420 is a wasteful number, since it uses less digits than its factorization.

31122420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74120 (or 74118 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31122420 is about 5578.7471711846. The cubic root of 31122420 is about 314.5510358882.

Adding to 31122420 its reverse (2422113), we get a palindrome (33544533).

The spelling of 31122420 in words is "thirty-one million, one hundred twenty-two thousand, four hundred twenty".