43661537 has 2 divisors, whose sum is σ = 43661538. Its totient is φ = 43661536.

The previous prime is 43661533. The next prime is 43661551. The reversal of 43661537 is 73516634.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43349056 + 312481 = 6584^2 + 559^2 .

It is a cyclic number.

It is not a de Polignac number, because 43661537 - 2² = 43661533 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 43661497 and 43661506.

It is not a weakly prime, because it can be changed into another prime (43661533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21830768 + 21830769.

It is an arithmetic number, because the mean of its divisors is an integer number (21830769).

Almost surely, 2^43661537 is an apocalyptic number.

It is an amenable number.

43661537 is a deficient number, since it is larger than the sum of its proper divisors (1).

43661537 is an equidigital number, since it uses as much as digits as its factorization.

43661537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 35.

The square root of 43661537 is about 6607.6877196187. The cubic root of 43661537 is about 352.1272810408.

The spelling of 43661537 in words is "forty-three million, six hundred sixty-one thousand, five hundred thirty-seven".