1687397927 has 4 divisors (see below), whose sum is σ = 1728554016. Its totient is φ = 1646241840.

The previous prime is 1687397897. The next prime is 1687397939. The reversal of 1687397927 is 7297937861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7297937861 = 19583 ⋅372667.

It is not a de Polignac number, because 1687397927 - 2⁸ = 1687397671 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 (1687397947) 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, 20577983 + ... + 20578064.

It is an arithmetic number, because the mean of its divisors is an integer number (432138504).

Almost surely, 2^1687397927 is an apocalyptic number.

1687397927 is a deficient number, since it is larger than the sum of its proper divisors (41156089).

1687397927 is an equidigital number, since it uses as much as digits as its factorization.

1687397927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41156088.

The product of its digits is 8001504, while the sum is 59.

The square root of 1687397927 is about 41077.9494011081. The cubic root of 1687397927 is about 1190.5267839310.

The spelling of 1687397927 in words is "one billion, six hundred eighty-seven million, three hundred ninety-seven thousand, nine hundred twenty-seven".