43897661 has 2 divisors, whose sum is σ = 43897662. Its totient is φ = 43897660.

The previous prime is 43897627. The next prime is 43897691. The reversal of 43897661 is 16679834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22562500 + 21335161 = 4750^2 + 4619^2 .

It is a cyclic number.

It is not a de Polignac number, because 43897661 - 2⁶ = 43897597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43897691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21948830 + 21948831.

It is an arithmetic number, because the mean of its divisors is an integer number (21948831).

Almost surely, 2^43897661 is an apocalyptic number.

It is an amenable number.

43897661 is a deficient number, since it is larger than the sum of its proper divisors (1).

43897661 is an equidigital number, since it uses as much as digits as its factorization.

43897661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The square root of 43897661 is about 6625.5309975880. The cubic root of 43897661 is about 352.7609147530.

The spelling of 43897661 in words is "forty-three million, eight hundred ninety-seven thousand, six hundred sixty-one".