100131021 has 6 divisors (see below), whose sum is σ = 144633710. Its totient is φ = 66754008.

The previous prime is 100131019. The next prime is 100131049. The reversal of 100131021 is 120131001.

It can be written as a sum of positive squares in only one way, i.e., 67469796 + 32661225 = 8214^2 + 5715^2 .

It is not a de Polignac number, because 100131021 - 2¹ = 100131019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 11125669 = 100131021 / (1 + 0 + 0 + 1 + 3 + 1 + 0 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 100130994 and 100131012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100131001) 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 5 ways as a sum of consecutive naturals, for example, 5562826 + ... + 5562843.

Almost surely, 2^100131021 is an apocalyptic number.

It is an amenable number.

100131021 is a deficient number, since it is larger than the sum of its proper divisors (44502689).

100131021 is a wasteful number, since it uses less digits than its factorization.

100131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11125675 (or 11125672 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 100131021 is about 10006.5489055918. The cubic root of 100131021 is about 464.3615100960.

Adding to 100131021 its reverse (120131001), we get a palindrome (220262022).

The spelling of 100131021 in words is "one hundred million, one hundred thirty-one thousand, twenty-one".