31520421021540 has 192 divisors, whose sum is σ = 96992494018560. Its totient is φ = 7584833280000.

The previous prime is 31520421021511. The next prime is 31520421021599. The reversal of 31520421021540 is 4512012402513.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 31520421021498 and 31520421021507.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 501878140 + ... + 501940940.

It is an arithmetic number, because the mean of its divisors is an integer number (505169239680).

Almost surely, 2^{31520421021540} is an apocalyptic number.

31520421021540 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 31520421021540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48496247009280).

31520421021540 is an abundant number, since it is smaller than the sum of its proper divisors (65472072997020).

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

31520421021540 is a wasteful number, since it uses less digits than its factorization.

31520421021540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68434 (or 68432 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The spelling of 31520421021540 in words is "thirty-one trillion, five hundred twenty billion, four hundred twenty-one million, twenty-one thousand, five hundred forty".