66443541 has 4 divisors (see below), whose sum is σ = 88591392. Its totient is φ = 44295692.

The previous prime is 66443501. The next prime is 66443563. The reversal of 66443541 is 14534466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66443541 - 2⁷ = 66443413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66443501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11073921 + ... + 11073926.

It is an arithmetic number, because the mean of its divisors is an integer number (22147848).

Almost surely, 2^66443541 is an apocalyptic number.

It is an amenable number.

66443541 is a deficient number, since it is larger than the sum of its proper divisors (22147851).

66443541 is a wasteful number, since it uses less digits than its factorization.

66443541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22147850.

The product of its digits is 34560, while the sum is 33.

The square root of 66443541 is about 8151.2907566839. The cubic root of 66443541 is about 405.0272623014.

The spelling of 66443541 in words is "sixty-six million, four hundred forty-three thousand, five hundred forty-one".