31401021440 has 104 divisors (see below), whose sum is σ = 75548607288. Its totient is φ = 12527861760.

The previous prime is 31401021413. The next prime is 31401021541. The reversal of 31401021440 is 4412010413.

It can be written as a sum of positive squares in 4 ways, for example, as 108826624 + 31292194816 = 10432^2 + 176896^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8866070 + ... + 8869610.

Almost surely, 2^31401021440 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 31401021440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37774303644).

31401021440 is an abundant number, since it is smaller than the sum of its proper divisors (44147585848).

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

31401021440 is an equidigital number, since it uses as much as digits as its factorization.

31401021440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4003 (or 3981 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 31401021440 its reverse (4412010413), we get a palindrome (35813031853).

The spelling of 31401021440 in words is "thirty-one billion, four hundred one million, twenty-one thousand, four hundred forty".