20031531540 has 96 divisors (see below), whose sum is σ = 57671792640. Its totient is φ = 5191910400.

The previous prime is 20031531529. The next prime is 20031531587. The reversal of 20031531540 is 4513513002.

It is a self number, because there is not a number n which added to its sum of digits gives 20031531540.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 646605 + ... + 676875.

It is an arithmetic number, because the mean of its divisors is an integer number (600747840).

Almost surely, 2^20031531540 is an apocalyptic number.

20031531540 is a gapful number since it is divisible by the number (20) 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 20031531540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28835896320).

20031531540 is an abundant number, since it is smaller than the sum of its proper divisors (37640261100).

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

20031531540 is a wasteful number, since it uses less digits than its factorization.

20031531540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30593 (or 30591 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 24.

The spelling of 20031531540 in words is "twenty billion, thirty-one million, five hundred thirty-one thousand, five hundred forty".