100520717021 has 2 divisors, whose sum is σ = 100520717022. Its totient is φ = 100520717020.

The previous prime is 100520716997. The next prime is 100520717023. The reversal of 100520717021 is 120717025001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75781831225 + 24738885796 = 275285^2 + 157286^2 .

It is a cyclic number.

It is not a de Polignac number, because 100520717021 - 2¹⁸ = 100520454877 is a prime.

It is a super-2 number, since 2×100520717021² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 100520717023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100520717023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50260358510 + 50260358511.

It is an arithmetic number, because the mean of its divisors is an integer number (50260358511).

Almost surely, 2^100520717021 is an apocalyptic number.

It is an amenable number.

100520717021 is a deficient number, since it is larger than the sum of its proper divisors (1).

100520717021 is an equidigital number, since it uses as much as digits as its factorization.

100520717021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980, while the sum is 26.

The spelling of 100520717021 in words is "one hundred billion, five hundred twenty million, seven hundred seventeen thousand, twenty-one".