1210010100021 has 6 divisors (see below), whose sum is σ = 1747792366710. Its totient is φ = 806673400008.

The previous prime is 1210010099891. The next prime is 1210010100023. The reversal of 1210010100021 is 1200010100121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 605884764996 + 604125335025 = 778386^2 + 777255^2 .

It is not a de Polignac number, because 1210010100021 - 2¹⁴ = 1210010083637 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: 134445566669 = 1210010100021 / (1 + 2 + 1 + 0 + 0 + 1 + 0 + 1 + 0 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 1210010099976 and 1210010100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210010100023) 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, 67222783326 + ... + 67222783343.

It is an arithmetic number, because the mean of its divisors is an integer number (291298727785).

Almost surely, 2^{1210010100021} is an apocalyptic number.

It is an amenable number.

1210010100021 is a deficient number, since it is larger than the sum of its proper divisors (537782266689).

1210010100021 is a wasteful number, since it uses less digits than its factorization.

1210010100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134445566675 (or 134445566672 counting only the distinct ones).

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

Adding to 1210010100021 its reverse (1200010100121), we get a palindrome (2410020200142).

The spelling of 1210010100021 in words is "one trillion, two hundred ten billion, ten million, one hundred thousand, twenty-one".