100009720621 has 4 divisors (see below), whose sum is σ = 100025604000. Its totient is φ = 99993837244.

The previous prime is 100009720607. The next prime is 100009720661. The reversal of 100009720621 is 126027900001.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 126027900001 = 197 ⋅639735533.

It is a cyclic number.

It is not a de Polignac number, because 100009720621 - 2⁷ = 100009720493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 100009720621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100009720661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7932241 + ... + 7944838.

It is an arithmetic number, because the mean of its divisors is an integer number (25006401000).

Almost surely, 2^100009720621 is an apocalyptic number.

It is an amenable number.

100009720621 is a deficient number, since it is larger than the sum of its proper divisors (15883379).

100009720621 is an equidigital number, since it uses as much as digits as its factorization.

100009720621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15883378.

The product of its (nonzero) digits is 1512, while the sum is 28.

The spelling of 100009720621 in words is "one hundred billion, nine million, seven hundred twenty thousand, six hundred twenty-one".