31209357942 has 128 divisors (see below), whose sum is σ = 82131148800. Its totient is φ = 8596368000.

The previous prime is 31209357941. The next prime is 31209357947. The reversal of 31209357942 is 24975390213.

31209357942 is a `hidden beast` number, since 3 + 1 + 209 + 357 + 94 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31209357941) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3147192 + ... + 3157092.

It is an arithmetic number, because the mean of its divisors is an integer number (641649600).

Almost surely, 2^31209357942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31209357942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41065574400).

31209357942 is an abundant number, since it is smaller than the sum of its proper divisors (50921790858).

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

31209357942 is a wasteful number, since it uses less digits than its factorization.

31209357942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10219 (or 10213 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 45.

The spelling of 31209357942 in words is "thirty-one billion, two hundred nine million, three hundred fifty-seven thousand, nine hundred forty-two".