2640978278 has 8 divisors (see below), whose sum is σ = 3962565768. Its totient is φ = 1320123024.

The previous prime is 2640978259. The next prime is 2640978299. The reversal of 2640978278 is 8728790462.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173951 + ... + 188522.

It is an arithmetic number, because the mean of its divisors is an integer number (495320721).

Almost surely, 2^2640978278 is an apocalyptic number.

2640978278 is a deficient number, since it is larger than the sum of its proper divisors (1321587490).

2640978278 is a wasteful number, since it uses less digits than its factorization.

2640978278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366118.

The product of its (nonzero) digits is 2709504, while the sum is 53.

The square root of 2640978278 is about 51390.4492877811. The cubic root of 2640978278 is about 1382.2553399455.

The spelling of 2640978278 in words is "two billion, six hundred forty million, nine hundred seventy-eight thousand, two hundred seventy-eight".