688631072 has 12 divisors (see below), whose sum is σ = 1355742486. Its totient is φ = 344315520.

The previous prime is 688631057. The next prime is 688631081. The reversal of 688631072 is 270136886.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 368793616 + 319837456 = 19204^2 + 17884^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10759829 + ... + 10759892.

Almost surely, 2^688631072 is an apocalyptic number.

It is an amenable number.

688631072 is a deficient number, since it is larger than the sum of its proper divisors (667111414).

688631072 is a wasteful number, since it uses less digits than its factorization.

688631072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21519731 (or 21519723 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 688631072 is about 26241.7810371171. The cubic root of 688631072 is about 883.0708281168.

The spelling of 688631072 in words is "six hundred eighty-eight million, six hundred thirty-one thousand, seventy-two".