771678749 has 4 divisors (see below), whose sum is σ = 812293440. Its totient is φ = 731064060.

The previous prime is 771678709. The next prime is 771678751. The reversal of 771678749 is 947876177.

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 not a de Polignac number, because 771678749 - 2²⁰ = 770630173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 771678694 and 771678703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (771678709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20307317 + ... + 20307354.

It is an arithmetic number, because the mean of its divisors is an integer number (203073360).

Almost surely, 2^771678749 is an apocalyptic number.

It is an amenable number.

771678749 is a deficient number, since it is larger than the sum of its proper divisors (40614691).

771678749 is a wasteful number, since it uses less digits than its factorization.

771678749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40614690.

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

The square root of 771678749 is about 27779.1063391175. The cubic root of 771678749 is about 917.2312587680.

The spelling of 771678749 in words is "seven hundred seventy-one million, six hundred seventy-eight thousand, seven hundred forty-nine".