31242020400 has 90 divisors (see below), whose sum is σ = 108418501620. Its totient is φ = 8331204480.

The previous prime is 31242020389. The next prime is 31242020401. The reversal of 31242020400 is 402024213.

31242020400 is a `hidden beast` number, since 3 + 1 + 242 + 0 + 20 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (90).

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

It is not an unprimeable number, because it can be changed into a prime (31242020401) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4335570 + ... + 4342769.

It is an arithmetic number, because the mean of its divisors is an integer number (1204650018).

Almost surely, 2^31242020400 is an apocalyptic number.

31242020400 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31242020400 is an abundant number, since it is smaller than the sum of its proper divisors (77176481220).

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

31242020400 is a wasteful number, since it uses less digits than its factorization.

31242020400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8678363 (or 8678349 counting only the distinct ones).

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

Adding to 31242020400 its reverse (402024213), we get a palindrome (31644044613).

The spelling of 31242020400 in words is "thirty-one billion, two hundred forty-two million, twenty thousand, four hundred".