43640261 has 8 divisors (see below), whose sum is σ = 50316864. Its totient is φ = 37074240.

The previous prime is 43640251. The next prime is 43640287. The reversal of 43640261 is 16204634.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-43640261 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 43640261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43640251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26795 + ... + 28376.

It is an arithmetic number, because the mean of its divisors is an integer number (6289608).

Almost surely, 2^43640261 is an apocalyptic number.

It is an amenable number.

43640261 is a deficient number, since it is larger than the sum of its proper divisors (6676603).

43640261 is a wasteful number, since it uses less digits than its factorization.

43640261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55291.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 43640261 is about 6606.0775805314. The cubic root of 43640261 is about 352.0700752575.

Adding to 43640261 its reverse (16204634), we get a palindrome (59844895).

The spelling of 43640261 in words is "forty-three million, six hundred forty thousand, two hundred sixty-one".