1687211993 has 8 divisors (see below), whose sum is σ = 1716128256. Its totient is φ = 1658336400.

The previous prime is 1687211957. The next prime is 1687212001. The reversal of 1687211993 is 3991127861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1687211993 - 2¹⁶ = 1687146457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1687211923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80330 + ... + 99132.

It is an arithmetic number, because the mean of its divisors is an integer number (214516032).

Almost surely, 2^1687211993 is an apocalyptic number.

It is an amenable number.

1687211993 is a deficient number, since it is larger than the sum of its proper divisors (28916263).

1687211993 is a wasteful number, since it uses less digits than its factorization.

1687211993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20335.

The product of its digits is 163296, while the sum is 47.

The square root of 1687211993 is about 41075.6861537333. The cubic root of 1687211993 is about 1190.4830543648.

The spelling of 1687211993 in words is "one billion, six hundred eighty-seven million, two hundred eleven thousand, nine hundred ninety-three".