31240020042 has 384 divisors, whose sum is σ = 91746091008. Its totient is φ = 7446297600.

The previous prime is 31240020041. The next prime is 31240020047. The reversal of 31240020042 is 24002004213.

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 = 31240019997 and 31240020024.

It is not an unprimeable number, because it can be changed into a prime (31240020041) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 68358678 + ... + 68359134.

It is an arithmetic number, because the mean of its divisors is an integer number (238922112).

Almost surely, 2^31240020042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31240020042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45873045504).

31240020042 is an abundant number, since it is smaller than the sum of its proper divisors (60506070966).

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

31240020042 is a wasteful number, since it uses less digits than its factorization.

31240020042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594 (or 591 counting only the distinct ones).

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

Adding to 31240020042 its reverse (24002004213), we get a palindrome (55242024255).

The spelling of 31240020042 in words is "thirty-one billion, two hundred forty million, twenty thousand, forty-two".