31638605020 has 144 divisors (see below), whose sum is σ = 75463105536. Its totient is φ = 11049696000.

The previous prime is 31638604981. The next prime is 31638605027. The reversal of 31638605020 is 2050683613.

It is a super-2 number, since 2×31638605020² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31638605027) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50140105 + ... + 50140735.

It is an arithmetic number, because the mean of its divisors is an integer number (524049344).

Almost surely, 2^31638605020 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 31638605020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37731552768).

31638605020 is an abundant number, since it is smaller than the sum of its proper divisors (43824500516).

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

31638605020 is a wasteful number, since it uses less digits than its factorization.

31638605020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980 (or 949 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The spelling of 31638605020 in words is "thirty-one billion, six hundred thirty-eight million, six hundred five thousand, twenty".