31100021040 has 160 divisors (see below), whose sum is σ = 105318259200. Its totient is φ = 7529103360.

The previous prime is 31100021023. The next prime is 31100021041. The reversal of 31100021040 is 4012000113.

It is a happy number.

It is a super-2 number, since 2×31100021040² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (31100021041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2022501 + ... + 2037819.

It is an arithmetic number, because the mean of its divisors is an integer number (658239120).

Almost surely, 2^31100021040 is an apocalyptic number.

31100021040 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 31100021040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52659129600).

31100021040 is an abundant number, since it is smaller than the sum of its proper divisors (74218238160).

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

31100021040 is a wasteful number, since it uses less digits than its factorization.

31100021040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16115 (or 16109 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 31100021040 its reverse (4012000113), we get a palindrome (35112021153).

The spelling of 31100021040 in words is "thirty-one billion, one hundred million, twenty-one thousand, forty".