1687387946 has 4 divisors (see below), whose sum is σ = 2531081922. Its totient is φ = 843693972.

The previous prime is 1687387943. The next prime is 1687387951. The reversal of 1687387946 is 6497837861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1034329921 + 653058025 = 32161^2 + 25555^2 .

It is not an unprimeable number, because it can be changed into a prime (1687387943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421846985 + ... + 421846988.

Almost surely, 2^1687387946 is an apocalyptic number.

1687387946 is a deficient number, since it is larger than the sum of its proper divisors (843693976).

1687387946 is an equidigital number, since it uses as much as digits as its factorization.

1687387946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843693975.

The product of its digits is 12192768, while the sum is 59.

The square root of 1687387946 is about 41077.8279123909. The cubic root of 1687387946 is about 1190.5244365947.

The spelling of 1687387946 in words is "one billion, six hundred eighty-seven million, three hundred eighty-seven thousand, nine hundred forty-six".