636777797 has 4 divisors (see below), whose sum is σ = 636834336. Its totient is φ = 636721260.

The previous prime is 636777773. The next prime is 636777803. The reversal of 636777797 is 797777636.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 636777797 - 2¹⁶ = 636712261 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 (636777997) 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, 4979 + ... + 36032.

It is an arithmetic number, because the mean of its divisors is an integer number (159208584).

Almost surely, 2^636777797 is an apocalyptic number.

It is an amenable number.

636777797 is a deficient number, since it is larger than the sum of its proper divisors (56539).

636777797 is a wasteful number, since it uses less digits than its factorization.

636777797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56538.

The product of its digits is 16336404, while the sum is 59.

The square root of 636777797 is about 25234.4565425927. The cubic root of 636777797 is about 860.3251866504.

The spelling of 636777797 in words is "six hundred thirty-six million, seven hundred seventy-seven thousand, seven hundred ninety-seven".