66621313 has 8 divisors (see below), whose sum is σ = 72938016. Its totient is φ = 60348000.

The previous prime is 66621311. The next prime is 66621329. The reversal of 66621313 is 31312666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66621313 - 2¹ = 66621311 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66621311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7588 + ... + 13813.

It is an arithmetic number, because the mean of its divisors is an integer number (9117252).

Almost surely, 2^66621313 is an apocalyptic number.

It is an amenable number.

66621313 is a deficient number, since it is larger than the sum of its proper divisors (6316703).

66621313 is a wasteful number, since it uses less digits than its factorization.

66621313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21695.

The product of its digits is 3888, while the sum is 28.

The square root of 66621313 is about 8162.1880032256. The cubic root of 66621313 is about 405.3881621250.

Adding to 66621313 its reverse (31312666), we get a palindrome (97933979).

The spelling of 66621313 in words is "sixty-six million, six hundred twenty-one thousand, three hundred thirteen".