768917561 has 4 divisors (see below), whose sum is σ = 778181712. Its totient is φ = 759653412.

The previous prime is 768917543. The next prime is 768917573. The reversal of 768917561 is 165719867.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-768917561 is a prime.

It is a super-2 number, since 2×768917561² = 1182468431228377442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (768967561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4631951 + ... + 4632116.

It is an arithmetic number, because the mean of its divisors is an integer number (194545428).

Almost surely, 2^768917561 is an apocalyptic number.

It is an amenable number.

768917561 is a deficient number, since it is larger than the sum of its proper divisors (9264151).

768917561 is an equidigital number, since it uses as much as digits as its factorization.

768917561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9264150.

The product of its digits is 635040, while the sum is 50.

The square root of 768917561 is about 27729.3627946983. The cubic root of 768917561 is about 916.1359520724.

The spelling of 768917561 in words is "seven hundred sixty-eight million, nine hundred seventeen thousand, five hundred sixty-one".