778797641 has 4 divisors (see below), whose sum is σ = 812658432. Its totient is φ = 744936852.

The previous prime is 778797601. The next prime is 778797667. The reversal of 778797641 is 146797877.

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, and also an emirpimes, since its reverse is a distinct semiprime: 146797877 = 1723 ⋅85199.

It is a cyclic number.

It is not a de Polignac number, because 778797641 - 2²² = 774603337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778797601) 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, 16930361 + ... + 16930406.

It is an arithmetic number, because the mean of its divisors is an integer number (203164608).

Almost surely, 2^778797641 is an apocalyptic number.

It is an amenable number.

778797641 is a deficient number, since it is larger than the sum of its proper divisors (33860791).

778797641 is a wasteful number, since it uses less digits than its factorization.

778797641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33860790.

The product of its digits is 4148928, while the sum is 56.

The square root of 778797641 is about 27906.9461066595. The cubic root of 778797641 is about 920.0431773214.

The spelling of 778797641 in words is "seven hundred seventy-eight million, seven hundred ninety-seven thousand, six hundred forty-one".