31240220440 has 128 divisors (see below), whose sum is σ = 83263360320. Its totient is φ = 10485995520.

The previous prime is 31240220437. The next prime is 31240220447. The reversal of 31240220440 is 4402204213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31240220447) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 669552 + ... + 714688.

Almost surely, 2^31240220440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31240220440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41631680160).

31240220440 is an abundant number, since it is smaller than the sum of its proper divisors (52023139880).

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

31240220440 is a wasteful number, since it uses less digits than its factorization.

31240220440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45194 (or 45168 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 31240220440 its reverse (4402204213), we get a palindrome (35642424653).

The spelling of 31240220440 in words is "thirty-one billion, two hundred forty million, two hundred twenty thousand, four hundred forty".