31869402640 has 80 divisors (see below), whose sum is σ = 75778721280. Its totient is φ = 12461529600.

The previous prime is 31869402629. The next prime is 31869402641. The reversal of 31869402640 is 4620496813.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (31869402641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 613357 + ... + 663283.

It is an arithmetic number, because the mean of its divisors is an integer number (947234016).

Almost surely, 2^31869402640 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 31869402640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37889360640).

31869402640 is an abundant number, since it is smaller than the sum of its proper divisors (43909318640).

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

31869402640 is a wasteful number, since it uses less digits than its factorization.

31869402640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50120 (or 50114 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 31869402640 in words is "thirty-one billion, eight hundred sixty-nine million, four hundred two thousand, six hundred forty".