1278608261 has 8 divisors (see below), whose sum is σ = 1461513984. Its totient is φ = 1095764400.

The previous prime is 1278608239. The next prime is 1278608321. The reversal of 1278608261 is 1628068721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1278608261 - 2⁶ = 1278608197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278608161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44171 + ... + 67143.

It is an arithmetic number, because the mean of its divisors is an integer number (182689248).

Almost surely, 2^1278608261 is an apocalyptic number.

It is an amenable number.

1278608261 is a deficient number, since it is larger than the sum of its proper divisors (182905723).

1278608261 is an equidigital number, since it uses as much as digits as its factorization.

1278608261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30931.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 1278608261 is about 35757.6322062857. The cubic root of 1278608261 is about 1085.3733871725.

The spelling of 1278608261 in words is "one billion, two hundred seventy-eight million, six hundred eight thousand, two hundred sixty-one".