1986804917 has 2 divisors, whose sum is σ = 1986804918. Its totient is φ = 1986804916.

The previous prime is 1986804899. The next prime is 1986804923. The reversal of 1986804917 is 7194086891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1612343716 + 374461201 = 40154^2 + 19351^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1986804917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1986806917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 993402458 + 993402459.

It is an arithmetic number, because the mean of its divisors is an integer number (993402459).

Almost surely, 2^1986804917 is an apocalyptic number.

It is an amenable number.

1986804917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1986804917 is an equidigital number, since it uses as much as digits as its factorization.

1986804917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 53.

The square root of 1986804917 is about 44573.5899047855. The cubic root of 1986804917 is about 1257.1441401816.

The spelling of 1986804917 in words is "one billion, nine hundred eighty-six million, eight hundred four thousand, nine hundred seventeen".