2640147778 has 4 divisors (see below), whose sum is σ = 3960221670. Its totient is φ = 1320073888.

The previous prime is 2640147749. The next prime is 2640147781. The reversal of 2640147778 is 8777410462.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2637130609 + 3017169 = 51353^2 + 1737^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660036943 + ... + 660036946.

Almost surely, 2^2640147778 is an apocalyptic number.

2640147778 is a deficient number, since it is larger than the sum of its proper divisors (1320073892).

2640147778 is a wasteful number, since it uses less digits than its factorization.

2640147778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320073891.

The product of its (nonzero) digits is 526848, while the sum is 46.

The square root of 2640147778 is about 51382.3683572488. The cubic root of 2640147778 is about 1382.1104336151.

The spelling of 2640147778 in words is "two billion, six hundred forty million, one hundred forty-seven thousand, seven hundred seventy-eight".