100517210021 has 4 divisors (see below), whose sum is σ = 102655874112. Its totient is φ = 98378545932.

The previous prime is 100517209973. The next prime is 100517210047. The reversal of 100517210021 is 120012715001.

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.

It is a cyclic number.

It is not a de Polignac number, because 100517210021 - 2⁶ = 100517209957 is a prime.

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 = 100517209975 and 100517210002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100517210081) 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, 1069331975 + ... + 1069332068.

It is an arithmetic number, because the mean of its divisors is an integer number (25663968528).

Almost surely, 2^100517210021 is an apocalyptic number.

It is an amenable number.

100517210021 is a deficient number, since it is larger than the sum of its proper divisors (2138664091).

100517210021 is an equidigital number, since it uses as much as digits as its factorization.

100517210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2138664090.

The product of its (nonzero) digits is 140, while the sum is 20.

Adding to 100517210021 its reverse (120012715001), we get a palindrome (220529925022).

The spelling of 100517210021 in words is "one hundred billion, five hundred seventeen million, two hundred ten thousand, twenty-one".