6561437 has 2 divisors, whose sum is σ = 6561438. Its totient is φ = 6561436.

The previous prime is 6561427. The next prime is 6561461. The reversal of 6561437 is 7341656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4618201 + 1943236 = 2149^2 + 1394^2 .

It is a cyclic number.

It is not a de Polignac number, because 6561437 - 2¹⁰ = 6560413 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6561427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280718 + 3280719.

It is an arithmetic number, because the mean of its divisors is an integer number (3280719).

Almost surely, 2^6561437 is an apocalyptic number.

It is an amenable number.

6561437 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561437 is an equidigital number, since it uses as much as digits as its factorization.

6561437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 32.

The square root of 6561437 is about 2561.5302067319. The cubic root of 6561437 is about 187.2117003456.

The spelling of 6561437 in words is "six million, five hundred sixty-one thousand, four hundred thirty-seven".