66431243 has 4 divisors (see below), whose sum is σ = 68226720. Its totient is φ = 64635768.

The previous prime is 66431219. The next prime is 66431263. The reversal of 66431243 is 34213466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66431243 - 2¹² = 66427147 is a prime.

It is a super-2 number, since 2×66431243² = 8826220093050098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66431263) 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, 897683 + ... + 897756.

It is an arithmetic number, because the mean of its divisors is an integer number (17056680).

Almost surely, 2^66431243 is an apocalyptic number.

66431243 is a deficient number, since it is larger than the sum of its proper divisors (1795477).

66431243 is a wasteful number, since it uses less digits than its factorization.

66431243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795476.

The product of its digits is 10368, while the sum is 29.

The square root of 66431243 is about 8150.5363627187. The cubic root of 66431243 is about 405.0022719986.

The spelling of 66431243 in words is "sixty-six million, four hundred thirty-one thousand, two hundred forty-three".