1311420021 has 4 divisors (see below), whose sum is σ = 1748560032. Its totient is φ = 874280012.

The previous prime is 1311420017. The next prime is 1311420023. The reversal of 1311420021 is 1200241131.

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 not a de Polignac number, because 1311420021 - 2² = 1311420017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311420023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218570001 + ... + 218570006.

It is an arithmetic number, because the mean of its divisors is an integer number (437140008).

Almost surely, 2^1311420021 is an apocalyptic number.

It is an amenable number.

1311420021 is a deficient number, since it is larger than the sum of its proper divisors (437140011).

1311420021 is an equidigital number, since it uses as much as digits as its factorization.

1311420021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437140010.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1311420021 is about 36213.5336718194. The cubic root of 1311420021 is about 1094.5793985223.

Adding to 1311420021 its reverse (1200241131), we get a palindrome (2511661152).

The spelling of 1311420021 in words is "one billion, three hundred eleven million, four hundred twenty thousand, twenty-one".