66431091 has 8 divisors (see below), whose sum is σ = 89161984. Its totient is φ = 43993800.

The previous prime is 66431063. The next prime is 66431093. The reversal of 66431091 is 19013466.

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

It is not a de Polignac number, because 66431091 - 2⁷ = 66430963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66431093) 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, 72871 + ... + 73776.

It is an arithmetic number, because the mean of its divisors is an integer number (11145248).

Almost surely, 2^66431091 is an apocalyptic number.

66431091 is a deficient number, since it is larger than the sum of its proper divisors (22730893).

66431091 is a wasteful number, since it uses less digits than its factorization.

66431091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146801.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 66431091 is about 8150.5270381737. The cubic root of 66431091 is about 405.0019631059.

The spelling of 66431091 in words is "sixty-six million, four hundred thirty-one thousand, ninety-one".