1278406013 has 4 divisors (see below), whose sum is σ = 1345690560. Its totient is φ = 1211121468.

The previous prime is 1278406009. The next prime is 1278406021. The reversal of 1278406013 is 3106048721.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3106048721 = 47 ⋅66086143.

It is a cyclic number.

It is not a de Polignac number, because 1278406013 - 2² = 1278406009 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278406313) 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, 33642245 + ... + 33642282.

It is an arithmetic number, because the mean of its divisors is an integer number (336422640).

Almost surely, 2^1278406013 is an apocalyptic number.

It is an amenable number.

1278406013 is a deficient number, since it is larger than the sum of its proper divisors (67284547).

1278406013 is an equidigital number, since it uses as much as digits as its factorization.

1278406013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67284546.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1278406013 is about 35754.8040548400. The cubic root of 1278406013 is about 1085.3161566720.

The spelling of 1278406013 in words is "one billion, two hundred seventy-eight million, four hundred six thousand, thirteen".