1210021100001 has 24 divisors (see below), whose sum is σ = 2051481508544. Its totient is φ = 672753042720.

The previous prime is 1210021099999. The next prime is 1210021100023. The reversal of 1210021100001 is 1000011200121.

It is a happy number.

It is not a de Polignac number, because 1210021100001 - 2¹ = 1210021099999 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1210021100401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 259547455 + ... + 259552116.

Almost surely, 2^{1210021100001} is an apocalyptic number.

It is an amenable number.

1210021100001 is a deficient number, since it is larger than the sum of its proper divisors (841460408543).

1210021100001 is a wasteful number, since it uses less digits than its factorization.

1210021100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519099621 (or 519099618 counting only the distinct ones).

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

Adding to 1210021100001 its reverse (1000011200121), we get a palindrome (2210032300122).

The spelling of 1210021100001 in words is "one trillion, two hundred ten billion, twenty-one million, one hundred thousand, one".