1201021021021 has 4 divisors (see below), whose sum is σ = 1201526290972. Its totient is φ = 1200515751072.

The previous prime is 1201021021009. The next prime is 1201021021037. The reversal of 1201021021021 is 1201201201021.

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 444103620921 + 756917400100 = 666411^2 + 870010^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201021021021 - 2⁹ = 1201021020509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1201021020992 and 1201021021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201021021061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 252631410 + ... + 252636163.

It is an arithmetic number, because the mean of its divisors is an integer number (300381572743).

Almost surely, 2^{1201021021021} is an apocalyptic number.

It is an amenable number.

1201021021021 is a deficient number, since it is larger than the sum of its proper divisors (505269951).

1201021021021 is an equidigital number, since it uses as much as digits as its factorization.

1201021021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505269950.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1201021021021 its reverse (1201201201021), we get a palindrome (2402222222042).

The spelling of 1201021021021 in words is "one trillion, two hundred one billion, twenty-one million, twenty-one thousand, twenty-one".