100402021021 has 4 divisors (see below), whose sum is σ = 102850850844. Its totient is φ = 97953191200.

The previous prime is 100402020989. The next prime is 100402021037. The reversal of 100402021021 is 120120204001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1671583225 + 98730437796 = 40885^2 + 314214^2 .

It is a cyclic number.

It is not a de Polignac number, because 100402021021 - 2⁵ = 100402020989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100402020992 and 100402021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100402021051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1224414850 + ... + 1224414931.

It is an arithmetic number, because the mean of its divisors is an integer number (25712712711).

Almost surely, 2^100402021021 is an apocalyptic number.

It is an amenable number.

100402021021 is a deficient number, since it is larger than the sum of its proper divisors (2448829823).

100402021021 is an equidigital number, since it uses as much as digits as its factorization.

100402021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2448829822.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 100402021021 its reverse (120120204001), we get a palindrome (220522225022).

The spelling of 100402021021 in words is "one hundred billion, four hundred two million, twenty-one thousand, twenty-one".