31551121242 has 32 divisors (see below), whose sum is σ = 72531316800. Its totient is φ = 10154383344.

The previous prime is 31551121237. The next prime is 31551121307. The reversal of 31551121242 is 24212115513.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 10072228 + ... + 10075359.

It is an arithmetic number, because the mean of its divisors is an integer number (2266603650).

Almost surely, 2^31551121242 is an apocalyptic number.

31551121242 is an abundant number, since it is smaller than the sum of its proper divisors (40980195558).

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

31551121242 is a wasteful number, since it uses less digits than its factorization.

31551121242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20147627 (or 20147621 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 31551121242 its reverse (24212115513), we get a palindrome (55763236755).

The spelling of 31551121242 in words is "thirty-one billion, five hundred fifty-one million, one hundred twenty-one thousand, two hundred forty-two".