2689406778 has 16 divisors (see below), whose sum is σ = 5379807456. Its totient is φ = 896303280.

The previous prime is 2689406777. The next prime is 2689406779. The reversal of 2689406778 is 8776049862.

It is an interprime number because it is at equal distance from previous prime (2689406777) and next prime (2689406779).

It is not an unprimeable number, because it can be changed into a prime (2689406773) 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, 3576 + ... + 73427.

It is an arithmetic number, because the mean of its divisors is an integer number (336237966).

Almost surely, 2^2689406778 is an apocalyptic number.

2689406778 is an abundant number, since it is smaller than the sum of its proper divisors (2690400678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2689406778 is a wasteful number, since it uses less digits than its factorization.

2689406778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82829.

The product of its (nonzero) digits is 8128512, while the sum is 57.

The square root of 2689406778 is about 51859.4907225283. The cubic root of 2689406778 is about 1390.6531750672.

The spelling of 2689406778 in words is "two billion, six hundred eighty-nine million, four hundred six thousand, seven hundred seventy-eight".