66831953 has 4 divisors (see below), whose sum is σ = 68638260. Its totient is φ = 65025648.

The previous prime is 66831931. The next prime is 66831967. The reversal of 66831953 is 35913866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35913866 = 2 ⋅17956933.

It can be written as a sum of positive squares in 2 ways, for example, as 37368769 + 29463184 = 6113^2 + 5428^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66831953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66831953.

It is not an unprimeable number, because it can be changed into a prime (66831923) 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, 903098 + ... + 903171.

It is an arithmetic number, because the mean of its divisors is an integer number (17159565).

Almost surely, 2^66831953 is an apocalyptic number.

It is an amenable number.

66831953 is a deficient number, since it is larger than the sum of its proper divisors (1806307).

66831953 is a wasteful number, since it uses less digits than its factorization.

66831953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806306.

The product of its digits is 116640, while the sum is 41.

The square root of 66831953 is about 8175.0812228381. The cubic root of 66831953 is about 405.8149581026.

The spelling of 66831953 in words is "sixty-six million, eight hundred thirty-one thousand, nine hundred fifty-three".