31200420420 has 72 divisors (see below), whose sum is σ = 101921381016. Its totient is φ = 7680102912.

The previous prime is 31200420413. The next prime is 31200420421. The reversal of 31200420420 is 2402400213.

31200420420 is a `hidden beast` number, since 3 + 1 + 200 + 42 + 0 + 420 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5089536 + 31195330884 = 2256^2 + 176622^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31200420393 and 31200420402.

It is not an unprimeable number, because it can be changed into a prime (31200420421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6664417 + ... + 6669096.

Almost surely, 2^31200420420 is an apocalyptic number.

31200420420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31200420420 is an abundant number, since it is smaller than the sum of its proper divisors (70720960596).

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

31200420420 is a wasteful number, since it uses less digits than its factorization.

31200420420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13333541 (or 13333536 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 31200420420 its reverse (2402400213), we get a palindrome (33602820633).

The spelling of 31200420420 in words is "thirty-one billion, two hundred million, four hundred twenty thousand, four hundred twenty".