1321121251 has 4 divisors (see below), whose sum is σ = 1335965400. Its totient is φ = 1306277104.

The previous prime is 1321121239. The next prime is 1321121257. The reversal of 1321121251 is 1521211231.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1321121251 - 2⁹ = 1321120739 is a prime.

It is a super-2 number, since 2×1321121251² = 3490722719687610002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321121257) 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, 7421941 + ... + 7422118.

It is an arithmetic number, because the mean of its divisors is an integer number (333991350).

Almost surely, 2^1321121251 is an apocalyptic number.

1321121251 is a deficient number, since it is larger than the sum of its proper divisors (14844149).

1321121251 is an equidigital number, since it uses as much as digits as its factorization.

1321121251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14844148.

The product of its digits is 120, while the sum is 19.

The square root of 1321121251 is about 36347.2316827568. The cubic root of 1321121251 is about 1097.2718208077.

Adding to 1321121251 its reverse (1521211231), we get a palindrome (2842332482).

The spelling of 1321121251 in words is "one billion, three hundred twenty-one million, one hundred twenty-one thousand, two hundred fifty-one".