31878537240 has 128 divisors (see below), whose sum is σ = 104558065920. Its totient is φ = 7711219200.

The previous prime is 31878537227. The next prime is 31878537277. The reversal of 31878537240 is 4273587813.

It is a super-2 number, since 2×31878537240² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 31878537240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 582327 + ... + 634713.

It is an arithmetic number, because the mean of its divisors is an integer number (816859890).

Almost surely, 2^31878537240 is an apocalyptic number.

31878537240 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31878537240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52279032960).

31878537240 is an abundant number, since it is smaller than the sum of its proper divisors (72679528680).

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

31878537240 is a wasteful number, since it uses less digits than its factorization.

31878537240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52873 (or 52869 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 48.

The spelling of 31878537240 in words is "thirty-one billion, eight hundred seventy-eight million, five hundred thirty-seven thousand, two hundred forty".