1665845437 has 2 divisors, whose sum is σ = 1665845438. Its totient is φ = 1665845436.

The previous prime is 1665845369. The next prime is 1665845483. The reversal of 1665845437 is 7345485661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1559776036 + 106069401 = 39494^2 + 10299^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665845437 - 2²⁷ = 1531627709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665845497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832922718 + 832922719.

It is an arithmetic number, because the mean of its divisors is an integer number (832922719).

Almost surely, 2^1665845437 is an apocalyptic number.

It is an amenable number.

1665845437 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665845437 is an equidigital number, since it uses as much as digits as its factorization.

1665845437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2419200, while the sum is 49.

The square root of 1665845437 is about 40814.7698388708. The cubic root of 1665845437 is about 1185.4363344166.

The spelling of 1665845437 in words is "one billion, six hundred sixty-five million, eight hundred forty-five thousand, four hundred thirty-seven".