1320399251 has 2 divisors, whose sum is σ = 1320399252. Its totient is φ = 1320399250.

The previous prime is 1320399233. The next prime is 1320399263. The reversal of 1320399251 is 1529930231.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1320399251 - 2⁶ = 1320399187 is a prime.

It is a super-2 number, since 2×1320399251² = 3486908364082722002, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1320399221) 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 as a sum of consecutive naturals, namely, 660199625 + 660199626.

It is an arithmetic number, because the mean of its divisors is an integer number (660199626).

Almost surely, 2^1320399251 is an apocalyptic number.

1320399251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320399251 is an equidigital number, since it uses as much as digits as its factorization.

1320399251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 1320399251 is about 36337.2983448137. The cubic root of 1320399251 is about 1097.0718960299.

The spelling of 1320399251 in words is "one billion, three hundred twenty million, three hundred ninety-nine thousand, two hundred fifty-one".