1687672221 has 16 divisors (see below), whose sum is σ = 2260327680. Its totient is φ = 1120078400.

The previous prime is 1687672211. The next prime is 1687672237. The reversal of 1687672221 is 1222767861.

It is a cyclic number.

It is not a de Polignac number, because 1687672221 - 2¹⁸ = 1687410077 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1687672211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 817036 + ... + 819098.

It is an arithmetic number, because the mean of its divisors is an integer number (141270480).

Almost surely, 2^1687672221 is an apocalyptic number.

It is an amenable number.

1687672221 is a deficient number, since it is larger than the sum of its proper divisors (572655459).

1687672221 is a wasteful number, since it uses less digits than its factorization.

1687672221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3156.

The product of its digits is 112896, while the sum is 42.

The square root of 1687672221 is about 41081.2879666643. The cubic root of 1687672221 is about 1190.5912889016.

The spelling of 1687672221 in words is "one billion, six hundred eighty-seven million, six hundred seventy-two thousand, two hundred twenty-one".