66144431 has 2 divisors, whose sum is σ = 66144432. Its totient is φ = 66144430.

The previous prime is 66144427. The next prime is 66144461. The reversal of 66144431 is 13444166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66144431 - 2² = 66144427 is a prime.

It is a super-2 number, since 2×66144431² = 8750171504627522, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66144394 and 66144403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66144461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33072215 + 33072216.

It is an arithmetic number, because the mean of its divisors is an integer number (33072216).

Almost surely, 2^66144431 is an apocalyptic number.

66144431 is a deficient number, since it is larger than the sum of its proper divisors (1).

66144431 is an equidigital number, since it uses as much as digits as its factorization.

66144431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 29.

The square root of 66144431 is about 8132.9226603971. The cubic root of 66144431 is about 404.4185753395.

Adding to 66144431 its reverse (13444166), we get a palindrome (79588597).

The spelling of 66144431 in words is "sixty-six million, one hundred forty-four thousand, four hundred thirty-one".