100031220 has 48 divisors (see below), whose sum is σ = 311209920. Its totient is φ = 26674848.

The previous prime is 100031189. The next prime is 100031263. The reversal of 100031220 is 22130001.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 92082 + ... + 93161.

It is an arithmetic number, because the mean of its divisors is an integer number (6483540).

Almost surely, 2^100031220 is an apocalyptic number.

100031220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100031220 is an abundant number, since it is smaller than the sum of its proper divisors (211178700).

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

100031220 is a wasteful number, since it uses less digits than its factorization.

100031220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185261 (or 185253 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 100031220 is about 10001.5608781830. The cubic root of 100031220 is about 464.2071818032.

Adding to 100031220 its reverse (22130001), we get a palindrome (122161221).

The spelling of 100031220 in words is "one hundred million, thirty-one thousand, two hundred twenty".