1278257923 has 4 divisors (see below), whose sum is σ = 1280995560. Its totient is φ = 1275520288.

The previous prime is 1278257909. The next prime is 1278257977. The reversal of 1278257923 is 3297528721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3297528721 = 563 ⋅5857067.

It is a cyclic number.

It is not a de Polignac number, because 1278257923 - 2⁵ = 1278257891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1278257983) 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, 1368118 + ... + 1369051.

It is an arithmetic number, because the mean of its divisors is an integer number (320248890).

Almost surely, 2^1278257923 is an apocalyptic number.

1278257923 is a deficient number, since it is larger than the sum of its proper divisors (2737637).

1278257923 is an equidigital number, since it uses as much as digits as its factorization.

1278257923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737636.

The product of its digits is 423360, while the sum is 46.

The square root of 1278257923 is about 35752.7330843392. The cubic root of 1278257923 is about 1085.2742475356.

The spelling of 1278257923 in words is "one billion, two hundred seventy-eight million, two hundred fifty-seven thousand, nine hundred twenty-three".