66426431 has 2 divisors, whose sum is σ = 66426432. Its totient is φ = 66426430.

The previous prime is 66426427. The next prime is 66426449. The reversal of 66426431 is 13462466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66426431 - 2² = 66426427 is a prime.

It is a super-2 number, since 2×66426431² = 8824941470795522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66426491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33213215 + 33213216.

It is an arithmetic number, because the mean of its divisors is an integer number (33213216).

Almost surely, 2^66426431 is an apocalyptic number.

66426431 is a deficient number, since it is larger than the sum of its proper divisors (1).

66426431 is an equidigital number, since it uses as much as digits as its factorization.

66426431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 32.

The square root of 66426431 is about 8150.2411620761. The cubic root of 66426431 is about 404.9924928751.

Adding to 66426431 its reverse (13462466), we get a palindrome (79888897).

The spelling of 66426431 in words is "sixty-six million, four hundred twenty-six thousand, four hundred thirty-one".