31242400220 has 12 divisors (see below), whose sum is σ = 65609040504. Its totient is φ = 12496960080.

The previous prime is 31242400187. The next prime is 31242400223. The reversal of 31242400220 is 2200424213.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1562120011 = 31242400220 / (3 + 1 + 2 + 4 + 2 + 4 + 0 + 0 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 31242400192 and 31242400201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31242400223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 781059986 + ... + 781060025.

It is an arithmetic number, because the mean of its divisors is an integer number (5467420042).

Almost surely, 2^31242400220 is an apocalyptic number.

It is an amenable number.

31242400220 is an abundant number, since it is smaller than the sum of its proper divisors (34366640284).

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

31242400220 is a wasteful number, since it uses less digits than its factorization.

31242400220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1562120020 (or 1562120018 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 31242400220 its reverse (2200424213), we get a palindrome (33442824433).

The spelling of 31242400220 in words is "thirty-one billion, two hundred forty-two million, four hundred thousand, two hundred twenty".