1321100251 has 2 divisors, whose sum is σ = 1321100252. Its totient is φ = 1321100250.

The previous prime is 1321100239. The next prime is 1321100257. The reversal of 1321100251 is 1520011231.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1321100251 - 2¹⁵ = 1321067483 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321100257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660550125 + 660550126.

It is an arithmetic number, because the mean of its divisors is an integer number (660550126).

Almost surely, 2^1321100251 is an apocalyptic number.

1321100251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321100251 is an equidigital number, since it uses as much as digits as its factorization.

1321100251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 1321100251 is about 36346.9428012866. The cubic root of 1321100251 is about 1097.2660068498.

Adding to 1321100251 its reverse (1520011231), we get a palindrome (2841111482).

The spelling of 1321100251 in words is "one billion, three hundred twenty-one million, one hundred thousand, two hundred fifty-one".