66450431 has 4 divisors (see below), whose sum is σ = 66467352. Its totient is φ = 66433512.

The previous prime is 66450421. The next prime is 66450481. The reversal of 66450431 is 13405466.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13405466 = 2 ⋅6702733.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66450431 is a prime.

It is a super-2 number, since 2×66450431² = 8831319560171522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66450394 and 66450403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66450401) 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, 836 + ... + 11558.

It is an arithmetic number, because the mean of its divisors is an integer number (16616838).

Almost surely, 2^66450431 is an apocalyptic number.

66450431 is a deficient number, since it is larger than the sum of its proper divisors (16921).

66450431 is a wasteful number, since it uses less digits than its factorization.

66450431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16920.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 66450431 is about 8151.7133781801. The cubic root of 66450431 is about 405.0412618632.

Adding to 66450431 its reverse (13405466), we get a palindrome (79855897).

The spelling of 66450431 in words is "sixty-six million, four hundred fifty thousand, four hundred thirty-one".