31201220100 has 72 divisors (see below), whose sum is σ = 90293283360. Its totient is φ = 8318689280.

The previous prime is 31201220081. The next prime is 31201220107. The reversal of 31201220100 is 102210213.

It is a super-2 number, since 2×31201220100² (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 (31201220107) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2836411 + ... + 2847389.

It is an arithmetic number, because the mean of its divisors is an integer number (1254073380).

Almost surely, 2^31201220100 is an apocalyptic number.

31201220100 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31201220100 is an abundant number, since it is smaller than the sum of its proper divisors (59092063260).

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

31201220100 is a wasteful number, since it uses less digits than its factorization.

31201220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20469 (or 20462 counting only the distinct ones).

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

Adding to 31201220100 its reverse (102210213), we get a palindrome (31303430313).

The spelling of 31201220100 in words is "thirty-one billion, two hundred one million, two hundred twenty thousand, one hundred".