1666232431 has 4 divisors (see below), whose sum is σ = 1668011632. Its totient is φ = 1664453232.

The previous prime is 1666232411. The next prime is 1666232443. The reversal of 1666232431 is 1342326661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666232431 is a prime.

It is a super-2 number, since 2×1666232431² = 5552661028232339522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666232411) 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, 888195 + ... + 890068.

It is an arithmetic number, because the mean of its divisors is an integer number (417002908).

Almost surely, 2^1666232431 is an apocalyptic number.

1666232431 is a deficient number, since it is larger than the sum of its proper divisors (1779201).

1666232431 is an equidigital number, since it uses as much as digits as its factorization.

1666232431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1779200.

The product of its digits is 31104, while the sum is 34.

The square root of 1666232431 is about 40819.5104208759. The cubic root of 1666232431 is about 1185.5281238905.

The spelling of 1666232431 in words is "one billion, six hundred sixty-six million, two hundred thirty-two thousand, four hundred thirty-one".