12101010021 has 6 divisors (see below), whose sum is σ = 17479236710. Its totient is φ = 8067340008.

The previous prime is 12101010017. The next prime is 12101010083. The reversal of 12101010021 is 12001010121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 6676687521 + 5424322500 = 81711^2 + 73650^2 .

It is not a de Polignac number, because 12101010021 - 2² = 12101010017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 1344556669 = 12101010021 / (1 + 2 + 1 + 0 + 1 + 0 + 1 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12101009985 and 12101010012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12101010001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 672278326 + ... + 672278343.

Almost surely, 2^12101010021 is an apocalyptic number.

It is an amenable number.

12101010021 is a deficient number, since it is larger than the sum of its proper divisors (5378226689).

12101010021 is a wasteful number, since it uses less digits than its factorization.

12101010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344556675 (or 1344556672 counting only the distinct ones).

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

Adding to 12101010021 its reverse (12001010121), we get a palindrome (24102020142).

It can be divided in two parts, 121010100 and 21, that added together give a palindrome (121010121).

The spelling of 12101010021 in words is "twelve billion, one hundred one million, ten thousand, twenty-one".