1688660925 has 24 divisors (see below), whose sum is σ = 3190766016. Its totient is φ = 771959040.

The previous prime is 1688660921. The next prime is 1688660959. The reversal of 1688660925 is 5290668861.

It is not a de Polignac number, because 1688660925 - 2² = 1688660921 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688660921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1607724 + ... + 1608773.

It is an arithmetic number, because the mean of its divisors is an integer number (132948584).

Almost surely, 2^1688660925 is an apocalyptic number.

1688660925 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1688660925 is a deficient number, since it is larger than the sum of its proper divisors (1502105091).

1688660925 is a wasteful number, since it uses less digits than its factorization.

1688660925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3216517 (or 3216512 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 51.

The square root of 1688660925 is about 41093.3197125762. The cubic root of 1688660925 is about 1190.8237417357.

The spelling of 1688660925 in words is "one billion, six hundred eighty-eight million, six hundred sixty thousand, nine hundred twenty-five".