1321800687 has 12 divisors (see below), whose sum is σ = 1979981640. Its totient is φ = 881200296.

The previous prime is 1321800679. The next prime is 1321800719. The reversal of 1321800687 is 7860081231.

It is not a de Polignac number, because 1321800687 - 2³ = 1321800679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321800637) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2719512 + ... + 2719997.

It is an arithmetic number, because the mean of its divisors is an integer number (164998470).

Almost surely, 2^1321800687 is an apocalyptic number.

1321800687 is a deficient number, since it is larger than the sum of its proper divisors (658180953).

1321800687 is an frugal number, since it uses more digits than its factorization.

1321800687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5439524 (or 5439512 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1321800687 is about 36356.5769428311. The cubic root of 1321800687 is about 1097.4598929240.

The spelling of 1321800687 in words is "one billion, three hundred twenty-one million, eight hundred thousand, six hundred eighty-seven".