774898639 has 2 divisors, whose sum is σ = 774898640. Its totient is φ = 774898638.

The previous prime is 774898633. The next prime is 774898687. The reversal of 774898639 is 936898477.

It is a weak prime.

It is an emirp because it is prime and its reverse (936898477) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-774898639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (774898633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387449319 + 387449320.

It is an arithmetic number, because the mean of its divisors is an integer number (387449320).

Almost surely, 2^774898639 is an apocalyptic number.

774898639 is a deficient number, since it is larger than the sum of its proper divisors (1).

774898639 is an equidigital number, since it uses as much as digits as its factorization.

774898639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18289152, while the sum is 61.

The square root of 774898639 is about 27837.0012573194. The cubic root of 774898639 is about 918.5052282428.

The spelling of 774898639 in words is "seven hundred seventy-four million, eight hundred ninety-eight thousand, six hundred thirty-nine".