1268849661 has 4 divisors (see below), whose sum is σ = 1691799552. Its totient is φ = 845899772.

The previous prime is 1268849657. The next prime is 1268849669. The reversal of 1268849661 is 1669488621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1268849661 - 2² = 1268849657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1268849669) 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, 211474941 + ... + 211474946.

It is an arithmetic number, because the mean of its divisors is an integer number (422949888).

Almost surely, 2^1268849661 is an apocalyptic number.

It is an amenable number.

1268849661 is a deficient number, since it is larger than the sum of its proper divisors (422949891).

1268849661 is an equidigital number, since it uses as much as digits as its factorization.

1268849661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422949890.

The product of its digits is 995328, while the sum is 51.

The square root of 1268849661 is about 35620.9160606518. The cubic root of 1268849661 is about 1082.6050684285.

The spelling of 1268849661 in words is "one billion, two hundred sixty-eight million, eight hundred forty-nine thousand, six hundred sixty-one".