6437581 has 2 divisors, whose sum is σ = 6437582. Its totient is φ = 6437580.

The previous prime is 6437579. The next prime is 6437597. The reversal of 6437581 is 1857346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5447556 + 990025 = 2334^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 6437581 - 2¹ = 6437579 is a prime.

It is a super-2 number, since 2×6437581² = 82884898263122, which contains 22 as substring.

Together with 6437579, it forms a pair of twin primes.

6437581 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6437521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3218790 + 3218791.

It is an arithmetic number, because the mean of its divisors is an integer number (3218791).

Almost surely, 2^6437581 is an apocalyptic number.

It is an amenable number.

6437581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6437581 is an equidigital number, since it uses as much as digits as its factorization.

6437581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 34.

The square root of 6437581 is about 2537.2388535571. The cubic root of 6437581 is about 186.0262517385.

It can be divided in two parts, 6 and 437581, that multiplied together give a triangular number (2625486 = T₂₂₉₁).

The spelling of 6437581 in words is "six million, four hundred thirty-seven thousand, five hundred eighty-one".