1688221457 has 32 divisors (see below), whose sum is σ = 1941408000. Its totient is φ = 1456922880.

The previous prime is 1688221439. The next prime is 1688221517. The reversal of 1688221457 is 7541228861.

It is not a de Polignac number, because 1688221457 - 2⁸ = 1688221201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1688221417) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1578719 + ... + 1579787.

It is an arithmetic number, because the mean of its divisors is an integer number (60669000).

Almost surely, 2^1688221457 is an apocalyptic number.

It is an amenable number.

1688221457 is a deficient number, since it is larger than the sum of its proper divisors (253186543).

1688221457 is a wasteful number, since it uses less digits than its factorization.

1688221457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241.

The product of its digits is 215040, while the sum is 44.

The square root of 1688221457 is about 41087.9721694805. The cubic root of 1688221457 is about 1190.7204302252.

The spelling of 1688221457 in words is "one billion, six hundred eighty-eight million, two hundred twenty-one thousand, four hundred fifty-seven".