1687661275 has 6 divisors (see below), whose sum is σ = 2092700012. Its totient is φ = 1350129000.

The previous prime is 1687661273. The next prime is 1687661299. The reversal of 1687661275 is 5721667861.

It is a happy number.

It is not a de Polignac number, because 1687661275 - 2¹ = 1687661273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1687661273) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33753201 + ... + 33753250.

Almost surely, 2^1687661275 is an apocalyptic number.

1687661275 is a deficient number, since it is larger than the sum of its proper divisors (405038737).

1687661275 is an equidigital number, since it uses as much as digits as its factorization.

1687661275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67506461 (or 67506456 counting only the distinct ones).

The product of its digits is 846720, while the sum is 49.

The square root of 1687661275 is about 41081.1547427771. The cubic root of 1687661275 is about 1190.5887148946.

The spelling of 1687661275 in words is "one billion, six hundred eighty-seven million, six hundred sixty-one thousand, two hundred seventy-five".