66813534 has 12 divisors (see below), whose sum is σ = 144762696. Its totient is φ = 22271172.

The previous prime is 66813533. The next prime is 66813541. The reversal of 66813534 is 43531866.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66813533) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1855914 + ... + 1855949.

It is an arithmetic number, because the mean of its divisors is an integer number (12063558).

Almost surely, 2^66813534 is an apocalyptic number.

66813534 is an abundant number, since it is smaller than the sum of its proper divisors (77949162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66813534 is a wasteful number, since it uses less digits than its factorization.

66813534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3711871 (or 3711868 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 66813534 is about 8173.9546120590. The cubic root of 66813534 is about 405.7776735794. Note that the first 3 decimals are identical.

The spelling of 66813534 in words is "sixty-six million, eight hundred thirteen thousand, five hundred thirty-four".