688577649 has 4 divisors (see below), whose sum is σ = 918103536. Its totient is φ = 459051764.

The previous prime is 688577647. The next prime is 688577671. The reversal of 688577649 is 946775886.

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 688577649 - 2¹ = 688577647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 688577592 and 688577601.

It is not an unprimeable number, because it can be changed into a prime (688577641) 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, 114762939 + ... + 114762944.

It is an arithmetic number, because the mean of its divisors is an integer number (229525884).

Almost surely, 2^688577649 is an apocalyptic number.

It is an amenable number.

688577649 is a deficient number, since it is larger than the sum of its proper divisors (229525887).

688577649 is a wasteful number, since it uses less digits than its factorization.

688577649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229525886.

The product of its digits is 20321280, while the sum is 60.

The square root of 688577649 is about 26240.7631177144. The cubic root of 688577649 is about 883.0479917414.

The spelling of 688577649 in words is "six hundred eighty-eight million, five hundred seventy-seven thousand, six hundred forty-nine".