688719545 has 4 divisors (see below), whose sum is σ = 826463460. Its totient is φ = 550975632.

The previous prime is 688719539. The next prime is 688719611. The reversal of 688719545 is 545917886.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 488100649 + 200618896 = 22093^2 + 14164^2 .

It is a cyclic number.

It is not a de Polignac number, because 688719545 - 2²⁰ = 687670969 is a prime.

It is a super-2 number, since 2×688719545² = 948669223330014050, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68871950 + ... + 68871959.

It is an arithmetic number, because the mean of its divisors is an integer number (206615865).

Almost surely, 2^688719545 is an apocalyptic number.

It is an amenable number.

688719545 is a deficient number, since it is larger than the sum of its proper divisors (137743915).

688719545 is a wasteful number, since it uses less digits than its factorization.

688719545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137743914.

The product of its digits is 2419200, while the sum is 53.

The square root of 688719545 is about 26243.4667107835. The cubic root of 688719545 is about 883.1086444856.

The spelling of 688719545 in words is "six hundred eighty-eight million, seven hundred nineteen thousand, five hundred forty-five".