689647540 has 12 divisors (see below), whose sum is σ = 1448259876. Its totient is φ = 275859008.

The previous prime is 689647537. The next prime is 689647547. The reversal of 689647540 is 45746986.

It can be written as a sum of positive squares in 2 ways, for example, as 373803556 + 315843984 = 19334^2 + 17772^2 .

It is a super-2 number, since 2×689647540² = 951227458856103200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689647547) 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, 17241169 + ... + 17241208.

It is an arithmetic number, because the mean of its divisors is an integer number (120688323).

Almost surely, 2^689647540 is an apocalyptic number.

It is an amenable number.

689647540 is an abundant number, since it is smaller than the sum of its proper divisors (758612336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

689647540 is a wasteful number, since it uses less digits than its factorization.

689647540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34482386 (or 34482384 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 49.

The square root of 689647540 is about 26261.1412547132. The cubic root of 689647540 is about 883.5051061068.

The spelling of 689647540 in words is "six hundred eighty-nine million, six hundred forty-seven thousand, five hundred forty".