1286421691 has 2 divisors, whose sum is σ = 1286421692. Its totient is φ = 1286421690.

The previous prime is 1286421683. The next prime is 1286421707. The reversal of 1286421691 is 1961246821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1286421691 - 2³ = 1286421683 is a prime.

It is not a weakly prime, because it can be changed into another prime (1286425691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643210845 + 643210846.

It is an arithmetic number, because the mean of its divisors is an integer number (643210846).

Almost surely, 2^1286421691 is an apocalyptic number.

1286421691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1286421691 is an equidigital number, since it uses as much as digits as its factorization.

1286421691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 40.

The square root of 1286421691 is about 35866.7212189796. The cubic root of 1286421691 is about 1087.5797634894.

The spelling of 1286421691 in words is "one billion, two hundred eighty-six million, four hundred twenty-one thousand, six hundred ninety-one".