1021201212121 has 4 divisors (see below), whose sum is σ = 1022856320052. Its totient is φ = 1019546104192.

The previous prime is 1021201212113. The next prime is 1021201212131. The reversal of 1021201212121 is 1212121021201.

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 175674986496 + 845526225625 = 419136^2 + 919525^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021201212121 - 2³ = 1021201212113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021201212095 and 1021201212104.

It is not an unprimeable number, because it can be changed into a prime (1021201212131) 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, 827553040 + ... + 827554273.

It is an arithmetic number, because the mean of its divisors is an integer number (255714080013).

Almost surely, 2^{1021201212121} is an apocalyptic number.

It is an amenable number.

1021201212121 is a deficient number, since it is larger than the sum of its proper divisors (1655107931).

1021201212121 is an equidigital number, since it uses as much as digits as its factorization.

1021201212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655107930.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1021201212121 its reverse (1212121021201), we get a palindrome (2233322233322).

The spelling of 1021201212121 in words is "one trillion, twenty-one billion, two hundred one million, two hundred twelve thousand, one hundred twenty-one".