43128961 has 2 divisors, whose sum is σ = 43128962. Its totient is φ = 43128960.

The previous prime is 43128959. The next prime is 43128973. The reversal of 43128961 is 16982134.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36978561 + 6150400 = 6081^2 + 2480^2 .

It is a cyclic number.

It is not a de Polignac number, because 43128961 - 2¹ = 43128959 is a prime.

Together with 43128959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (43128931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21564480 + 21564481.

It is an arithmetic number, because the mean of its divisors is an integer number (21564481).

Almost surely, 2^43128961 is an apocalyptic number.

It is an amenable number.

43128961 is a deficient number, since it is larger than the sum of its proper divisors (1).

43128961 is an equidigital number, since it uses as much as digits as its factorization.

43128961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 43128961 is about 6567.2643467429. The cubic root of 43128961 is about 350.6896903822.

It can be divided in two parts, 431 and 28961, that added together give a palindrome (29392).

The spelling of 43128961 in words is "forty-three million, one hundred twenty-eight thousand, nine hundred sixty-one".