6645637 has 2 divisors, whose sum is σ = 6645638. Its totient is φ = 6645636.

The previous prime is 6645619. The next prime is 6645641. The reversal of 6645637 is 7365466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5377761 + 1267876 = 2319^2 + 1126^2 .

It is a cyclic number.

It is not a de Polignac number, because 6645637 - 2¹¹ = 6643589 is a prime.

It is a super-2 number, since 2×6645637² = 88328982271538, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6645596 and 6645605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6645677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322818 + 3322819.

It is an arithmetic number, because the mean of its divisors is an integer number (3322819).

Almost surely, 2^6645637 is an apocalyptic number.

It is an amenable number.

6645637 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645637 is an equidigital number, since it uses as much as digits as its factorization.

6645637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 37.

The square root of 6645637 is about 2577.9133034297. The cubic root of 6645637 is about 188.0091005856.

The spelling of 6645637 in words is "six million, six hundred forty-five thousand, six hundred thirty-seven".