2640947986 has 4 divisors (see below), whose sum is σ = 3961421982. Its totient is φ = 1320473992.

The previous prime is 2640947957. The next prime is 2640947989. The reversal of 2640947986 is 6897490462.

It is a happy number.

2640947986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 2598450625 + 42497361 = 50975^2 + 6519^2 .

It is not an unprimeable number, because it can be changed into a prime (2640947989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660236995 + ... + 660236998.

Almost surely, 2^2640947986 is an apocalyptic number.

2640947986 is a deficient number, since it is larger than the sum of its proper divisors (1320473996).

2640947986 is a wasteful number, since it uses less digits than its factorization.

2640947986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320473995.

The product of its (nonzero) digits is 5225472, while the sum is 55.

The square root of 2640947986 is about 51390.1545629121. The cubic root of 2640947986 is about 1382.2500551061.

The spelling of 2640947986 in words is "two billion, six hundred forty million, nine hundred forty-seven thousand, nine hundred eighty-six".