1200001102021 has 4 divisors (see below), whose sum is σ = 1200315160044. Its totient is φ = 1199687044000.

The previous prime is 1200001101983. The next prime is 1200001102051. The reversal of 1200001102021 is 1202011000021.

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 1125532149921 + 74468952100 = 1060911^2 + 272890^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200001102021 - 2²⁵ = 1199967547589 is a prime.

It is a super-2 number, since 2×1200001102021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200001101989 and 1200001102007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200001102051) 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, 157023280 + ... + 157030921.

It is an arithmetic number, because the mean of its divisors is an integer number (300078790011).

Almost surely, 2^{1200001102021} is an apocalyptic number.

It is an amenable number.

1200001102021 is a deficient number, since it is larger than the sum of its proper divisors (314058023).

1200001102021 is an equidigital number, since it uses as much as digits as its factorization.

1200001102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314058022.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1200001102021 its reverse (1202011000021), we get a palindrome (2402012102042).

The spelling of 1200001102021 in words is "one trillion, two hundred billion, one million, one hundred two thousand, twenty-one".