688690542 has 16 divisors (see below), whose sum is σ = 1378910592. Its totient is φ = 229308600.

The previous prime is 688690501. The next prime is 688690567. The reversal of 688690542 is 245096886.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 688690491 and 688690500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57834 + ... + 68717.

It is an arithmetic number, because the mean of its divisors is an integer number (86181912).

Almost surely, 2^688690542 is an apocalyptic number.

688690542 is an abundant number, since it is smaller than the sum of its proper divisors (690220050).

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

688690542 is a wasteful number, since it uses less digits than its factorization.

688690542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127463.

The product of its (nonzero) digits is 829440, while the sum is 48.

The square root of 688690542 is about 26242.9141293417. The cubic root of 688690542 is about 883.0962479739.

The spelling of 688690542 in words is "six hundred eighty-eight million, six hundred ninety thousand, five hundred forty-two".