677707721 has 4 divisors (see below), whose sum is σ = 677868672. Its totient is φ = 677546772.

The previous prime is 677707717. The next prime is 677707729. The reversal of 677707721 is 127707776.

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 677707721 - 2² = 677707717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (677707729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73985 + ... + 82638.

It is an arithmetic number, because the mean of its divisors is an integer number (169467168).

Almost surely, 2^677707721 is an apocalyptic number.

It is an amenable number.

677707721 is a deficient number, since it is larger than the sum of its proper divisors (160951).

677707721 is a wasteful number, since it uses less digits than its factorization.

677707721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160950.

The product of its (nonzero) digits is 201684, while the sum is 44.

The square root of 677707721 is about 26032.8200738990. The cubic root of 677707721 is about 878.3767082803.

Subtracting from 677707721 its reverse (127707776), we obtain a palindrome (549999945).

The spelling of 677707721 in words is "six hundred seventy-seven million, seven hundred seven thousand, seven hundred twenty-one".