771639668 has 6 divisors (see below), whose sum is σ = 1350369426. Its totient is φ = 385819832.

The previous prime is 771639653. The next prime is 771639679. The reversal of 771639668 is 866936177.

It can be written as a sum of positive squares in only one way, i.e., 732351844 + 39287824 = 27062^2 + 6268^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96454955 + ... + 96454962.

It is an arithmetic number, because the mean of its divisors is an integer number (225061571).

Almost surely, 2^771639668 is an apocalyptic number.

It is an amenable number.

771639668 is a deficient number, since it is larger than the sum of its proper divisors (578729758).

771639668 is a wasteful number, since it uses less digits than its factorization.

771639668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192909921 (or 192909919 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 53.

The square root of 771639668 is about 27778.4029058548. The cubic root of 771639668 is about 917.2157743798.

The spelling of 771639668 in words is "seven hundred seventy-one million, six hundred thirty-nine thousand, six hundred sixty-eight".