681719569 has 4 divisors (see below), whose sum is σ = 682292196. Its totient is φ = 681146944.

The previous prime is 681719557. The next prime is 681719603. The reversal of 681719569 is 965917186.

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 531901969 + 149817600 = 23063^2 + 12240^2 .

It is a cyclic number.

It is not a de Polignac number, because 681719569 - 2¹³ = 681711377 is a prime.

It is a super-2 number, since 2×681719569² = 929483141515091522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681719509) 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, 284524 + ... + 286909.

It is an arithmetic number, because the mean of its divisors is an integer number (170573049).

Almost surely, 2^681719569 is an apocalyptic number.

It is an amenable number.

681719569 is a deficient number, since it is larger than the sum of its proper divisors (572627).

681719569 is a wasteful number, since it uses less digits than its factorization.

681719569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572626.

The product of its digits is 816480, while the sum is 52.

The square root of 681719569 is about 26109.7600333668. The cubic root of 681719569 is about 880.1065508896.

The spelling of 681719569 in words is "six hundred eighty-one million, seven hundred nineteen thousand, five hundred sixty-nine".