669938688 has 220 divisors, whose sum is σ = 2059765092. Its totient is φ = 216760320.

The previous prime is 669938683. The next prime is 669938699. The reversal of 669938688 is 886839966.

It can be written as a sum of positive squares in 2 ways, for example, as 361304064 + 308634624 = 19008^2 + 17568^2 .

It is a super-2 number, since 2×669938688² = 897635691358322688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (26873856) is a multiple of the sum of its prime divisors (243).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669938683) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3400606 + ... + 3400802.

Almost surely, 2^669938688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669938688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029882546).

669938688 is an abundant number, since it is smaller than the sum of its proper divisors (1389826404).

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

669938688 is a wasteful number, since it uses less digits than its factorization.

669938688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 243 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 63.

The square root of 669938688 is about 25883.1738393884. The cubic root of 669938688 is about 875.0073198843.

The spelling of 669938688 in words is "six hundred sixty-nine million, nine hundred thirty-eight thousand, six hundred eighty-eight".