100131220 has 24 divisors (see below), whose sum is σ = 240315264. Its totient is φ = 34330656.

The previous prime is 100131211. The next prime is 100131223. The reversal of 100131220 is 22131001.

It is a super-2 number, since 2×100131220² = 20052522437376800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 100131197 and 100131206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100131223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 357472 + ... + 357751.

It is an arithmetic number, because the mean of its divisors is an integer number (10013136).

Almost surely, 2^100131220 is an apocalyptic number.

100131220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100131220 is an abundant number, since it is smaller than the sum of its proper divisors (140184044).

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

100131220 is a wasteful number, since it uses less digits than its factorization.

100131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715239 (or 715237 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 100131220 is about 10006.5588490749. The cubic root of 100131220 is about 464.3618177192.

Adding to 100131220 its reverse (22131001), we get a palindrome (122262221).

The spelling of 100131220 in words is "one hundred million, one hundred thirty-one thousand, two hundred twenty".