66631451 has 4 divisors (see below), whose sum is σ = 66705504. Its totient is φ = 66557400.

The previous prime is 66631427. The next prime is 66631463. The reversal of 66631451 is 15413666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15413666 = 2 ⋅7706833.

It is a cyclic number.

It is not a de Polignac number, because 66631451 - 2⁶ = 66631387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66631471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35660 + ... + 37481.

It is an arithmetic number, because the mean of its divisors is an integer number (16676376).

Almost surely, 2^66631451 is an apocalyptic number.

66631451 is a deficient number, since it is larger than the sum of its proper divisors (74053).

66631451 is an equidigital number, since it uses as much as digits as its factorization.

66631451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74052.

The product of its digits is 12960, while the sum is 32.

The square root of 66631451 is about 8162.8090140588. The cubic root of 66631451 is about 405.4087241972.

The spelling of 66631451 in words is "sixty-six million, six hundred thirty-one thousand, four hundred fifty-one".