210100001010021 has 12 divisors (see below), whose sum is σ = 303590470611948. Its totient is φ = 140014655936064.

The previous prime is 210100001009963. The next prime is 210100001010071. The reversal of 210100001010021 is 120010100001012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 62844542777025 + 147255458232996 = 7927455^2 + 12134886^2 .

It is not a de Polignac number, because 210100001010021 - 2⁷ = 210100001009893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 210100001009985 and 210100001010012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210100001010071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4334258080 + ... + 4334306553.

It is an arithmetic number, because the mean of its divisors is an integer number (25299205884329).

Almost surely, 2^{210100001010021} is an apocalyptic number.

It is an amenable number.

210100001010021 is a deficient number, since it is larger than the sum of its proper divisors (93490469601927).

210100001010021 is a wasteful number, since it uses less digits than its factorization.

210100001010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8668567332 (or 8668567329 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 210100001010021 its reverse (120010100001012), we get a palindrome (330110101011033).

The spelling of 210100001010021 in words is "two hundred ten trillion, one hundred billion, one million, ten thousand, twenty-one".