6661778734 has 16 divisors (see below), whose sum is σ = 10770450768. Its totient is φ = 3072062592.

The previous prime is 6661778723. The next prime is 6661778737. The reversal of 6661778734 is 4378771666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661778737) 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, 77067 + ... + 138790.

It is an arithmetic number, because the mean of its divisors is an integer number (673153173).

Almost surely, 2^6661778734 is an apocalyptic number.

6661778734 is a deficient number, since it is larger than the sum of its proper divisors (4108672034).

6661778734 is a wasteful number, since it uses less digits than its factorization.

6661778734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217059.

The product of its digits is 7112448, while the sum is 55.

The square root of 6661778734 is about 81619.7202519097. The cubic root of 6661778734 is about 1881.6119732260.

The spelling of 6661778734 in words is "six billion, six hundred sixty-one million, seven hundred seventy-eight thousand, seven hundred thirty-four".