31221320140 has 24 divisors (see below), whose sum is σ = 65584773072. Its totient is φ = 12484718400.

The previous prime is 31221320101. The next prime is 31221320161. The reversal of 31221320140 is 4102312213.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170434 + ... + 302473.

It is an arithmetic number, because the mean of its divisors is an integer number (2732698878).

Almost surely, 2^31221320140 is an apocalyptic number.

It is an amenable number.

31221320140 is an abundant number, since it is smaller than the sum of its proper divisors (34363452932).

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

31221320140 is a wasteful number, since it uses less digits than its factorization.

31221320140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476217 (or 476215 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31221320140 its reverse (4102312213), we get a palindrome (35323632353).

The spelling of 31221320140 in words is "thirty-one billion, two hundred twenty-one million, three hundred twenty thousand, one hundred forty".