1261451099 has 2 divisors, whose sum is σ = 1261451100. Its totient is φ = 1261451098.

The previous prime is 1261451069. The next prime is 1261451161. The reversal of 1261451099 is 9901541621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1261451099 - 2¹⁶ = 1261385563 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1261451069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630725549 + 630725550.

It is an arithmetic number, because the mean of its divisors is an integer number (630725550).

Almost surely, 2^1261451099 is an apocalyptic number.

1261451099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261451099 is an equidigital number, since it uses as much as digits as its factorization.

1261451099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 1261451099 is about 35516.9128585242. The cubic root of 1261451099 is about 1080.4967704925.

The spelling of 1261451099 in words is "one billion, two hundred sixty-one million, four hundred fifty-one thousand, ninety-nine".