771716621 has 8 divisors (see below), whose sum is σ = 838705560. Its totient is φ = 705817152.

The previous prime is 771716587. The next prime is 771716633. The reversal of 771716621 is 126617177.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 275095396 + 496621225 = 16586^2 + 22285^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 771716621 - 2⁶ = 771716557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (771716681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 270890 + ... + 273723.

It is an arithmetic number, because the mean of its divisors is an integer number (104838195).

Almost surely, 2^771716621 is an apocalyptic number.

It is an amenable number.

771716621 is a deficient number, since it is larger than the sum of its proper divisors (66988939).

771716621 is a wasteful number, since it uses less digits than its factorization.

771716621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544735.

The product of its digits is 24696, while the sum is 38.

The square root of 771716621 is about 27779.7879941514. The cubic root of 771716621 is about 917.2462636363.

The spelling of 771716621 in words is "seven hundred seventy-one million, seven hundred sixteen thousand, six hundred twenty-one".