1221313130021 has 4 divisors (see below), whose sum is σ = 1221372602112. Its totient is φ = 1221253657932.

The previous prime is 1221313130003. The next prime is 1221313130029. The reversal of 1221313130021 is 1200313131221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221313130021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221313129975 and 1221313130002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221313130029) 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, 29705231 + ... + 29746316.

It is an arithmetic number, because the mean of its divisors is an integer number (305343150528).

Almost surely, 2^{1221313130021} is an apocalyptic number.

It is an amenable number.

1221313130021 is a deficient number, since it is larger than the sum of its proper divisors (59472091).

1221313130021 is an equidigital number, since it uses as much as digits as its factorization.

1221313130021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59472090.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 1221313130021 its reverse (1200313131221), we get a palindrome (2421626261242).

The spelling of 1221313130021 in words is "one trillion, two hundred twenty-one billion, three hundred thirteen million, one hundred thirty thousand, twenty-one".