677643521 has 2 divisors, whose sum is σ = 677643522. Its totient is φ = 677643520.

The previous prime is 677643469. The next prime is 677643523. The reversal of 677643521 is 125346776.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 650811121 + 26832400 = 25511^2 + 5180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-677643521 is a prime.

Together with 677643523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (677643523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 338821760 + 338821761.

It is an arithmetic number, because the mean of its divisors is an integer number (338821761).

Almost surely, 2^677643521 is an apocalyptic number.

It is an amenable number.

677643521 is a deficient number, since it is larger than the sum of its proper divisors (1).

677643521 is an equidigital number, since it uses as much as digits as its factorization.

677643521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 41.

The square root of 677643521 is about 26031.5869858140. The cubic root of 677643521 is about 878.3489708729.

The spelling of 677643521 in words is "six hundred seventy-seven million, six hundred forty-three thousand, five hundred twenty-one".