66954451 has 4 divisors (see below), whose sum is σ = 69114304. Its totient is φ = 64794600.

The previous prime is 66954443. The next prime is 66954463. The reversal of 66954451 is 15445966.

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: 15445966 = 2 ⋅7722983.

It is a cyclic number.

It is not a de Polignac number, because 66954451 - 2³ = 66954443 is a prime.

It is a super-2 number, since 2×66954451² = 8965797017422802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66954401) 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, 1079880 + ... + 1079941.

It is an arithmetic number, because the mean of its divisors is an integer number (17278576).

Almost surely, 2^66954451 is an apocalyptic number.

66954451 is a deficient number, since it is larger than the sum of its proper divisors (2159853).

66954451 is a wasteful number, since it uses less digits than its factorization.

66954451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2159852.

The product of its digits is 129600, while the sum is 40.

The square root of 66954451 is about 8182.5699508162. The cubic root of 66954451 is about 406.0627496499.

The spelling of 66954451 in words is "sixty-six million, nine hundred fifty-four thousand, four hundred fifty-one".