65661213 has 8 divisors (see below), whose sum is σ = 89683776. Its totient is φ = 42706400.

The previous prime is 65661181. The next prime is 65661221. The reversal of 65661213 is 31216656.

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 65661213 - 2⁵ = 65661181 is a prime.

It is a super-2 number, since 2×65661213² = 8622789785262738, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65666213) 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, 266793 + ... + 267038.

It is an arithmetic number, because the mean of its divisors is an integer number (11210472).

Almost surely, 2^65661213 is an apocalyptic number.

It is an amenable number.

65661213 is a deficient number, since it is larger than the sum of its proper divisors (24022563).

65661213 is a wasteful number, since it uses less digits than its factorization.

65661213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533875.

The product of its digits is 6480, while the sum is 30.

The square root of 65661213 is about 8103.1606796361. The cubic root of 65661213 is about 403.4313409954.

Adding to 65661213 its reverse (31216656), we get a palindrome (96877869).

The spelling of 65661213 in words is "sixty-five million, six hundred sixty-one thousand, two hundred thirteen".