1688075221 has 4 divisors (see below), whose sum is σ = 1929228832. Its totient is φ = 1446921612.

The previous prime is 1688075219. The next prime is 1688075243. The reversal of 1688075221 is 1225708861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1688075221 - 2¹ = 1688075219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688075201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120576795 + ... + 120576808.

It is an arithmetic number, because the mean of its divisors is an integer number (482307208).

Almost surely, 2^1688075221 is an apocalyptic number.

It is an amenable number.

1688075221 is a deficient number, since it is larger than the sum of its proper divisors (241153611).

1688075221 is an equidigital number, since it uses as much as digits as its factorization.

1688075221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241153610.

The product of its (nonzero) digits is 53760, while the sum is 40.

The square root of 1688075221 is about 41086.1925833972. The cubic root of 1688075221 is about 1190.6860486338.

The spelling of 1688075221 in words is "one billion, six hundred eighty-eight million, seventy-five thousand, two hundred twenty-one".