6866742491 has 4 divisors (see below), whose sum is σ = 7847705712. Its totient is φ = 5885779272.

The previous prime is 6866742479. The next prime is 6866742499. The reversal of 6866742491 is 1942476686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1942476686 = 2 ⋅971238343.

It is a cyclic number.

It is not a de Polignac number, because 6866742491 - 2¹⁸ = 6866480347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6866742499) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 490481600 + ... + 490481613.

It is an arithmetic number, because the mean of its divisors is an integer number (1961926428).

Almost surely, 2^6866742491 is an apocalyptic number.

6866742491 is a deficient number, since it is larger than the sum of its proper divisors (980963221).

6866742491 is an equidigital number, since it uses as much as digits as its factorization.

6866742491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980963220.

The product of its digits is 3483648, while the sum is 53.

The square root of 6866742491 is about 82865.8101450773. The cubic root of 6866742491 is about 1900.7146426191.

The spelling of 6866742491 in words is "six billion, eight hundred sixty-six million, seven hundred forty-two thousand, four hundred ninety-one".