66431542 has 4 divisors (see below), whose sum is σ = 99647316. Its totient is φ = 33215770.

The previous prime is 66431531. The next prime is 66431549. The reversal of 66431542 is 24513466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24513466 = 2 ⋅12256733.

It is a super-3 number, since 3×66431542³ (a number of 24 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66431549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16607884 + ... + 16607887.

It is an arithmetic number, because the mean of its divisors is an integer number (24911829).

Almost surely, 2^66431542 is an apocalyptic number.

66431542 is a deficient number, since it is larger than the sum of its proper divisors (33215774).

66431542 is a wasteful number, since it uses less digits than its factorization.

66431542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33215773.

The product of its digits is 17280, while the sum is 31.

The square root of 66431542 is about 8150.5547050492. The cubic root of 66431542 is about 405.0028796219.

The spelling of 66431542 in words is "sixty-six million, four hundred thirty-one thousand, five hundred forty-two".