10101010100021 has 4 divisors (see below), whose sum is σ = 10101180092844. Its totient is φ = 10100840107200.

The previous prime is 10101010099949. The next prime is 10101010100023. The reversal of 10101010100021 is 12000101010101.

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 2088068350225 + 8012941749796 = 1445015^2 + 2830714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10101010100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10101010099981 and 10101010100008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10101010100023) 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, 84907250 + ... + 85026131.

It is an arithmetic number, because the mean of its divisors is an integer number (2525295023211).

Almost surely, 2^{10101010100021} is an apocalyptic number.

It is an amenable number.

10101010100021 is a deficient number, since it is larger than the sum of its proper divisors (169992823).

10101010100021 is an equidigital number, since it uses as much as digits as its factorization.

10101010100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169992822.

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 10101010100021 its reverse (12000101010101), we get a palindrome (22101111110122).

The spelling of 10101010100021 in words is "ten trillion, one hundred one billion, ten million, one hundred thousand, twenty-one".