1607981 has 2 divisors, whose sum is σ = 1607982. Its totient is φ = 1607980.

The previous prime is 1607941. The next prime is 1607987. The reversal of 1607981 is 1897061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 885481 + 722500 = 941^2 + 850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1607981 is a prime.

It is a super-2 number, since 2×1607981² = 5171205792722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1607987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803990 + 803991.

It is an arithmetic number, because the mean of its divisors is an integer number (803991).

2^1607981 is an apocalyptic number.

It is an amenable number.

1607981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1607981 is an equidigital number, since it uses as much as digits as its factorization.

1607981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 1607981 is about 1268.0619070061. The cubic root of 1607981 is about 117.1548586186.

The spelling of 1607981 in words is "one million, six hundred seven thousand, nine hundred eighty-one".