66236621 has 4 divisors (see below), whose sum is σ = 72258144. Its totient is φ = 60215100.

The previous prime is 66236617. The next prime is 66236627. The reversal of 66236621 is 12663266.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 66236621 - 2² = 66236617 is a prime.

It is a super-2 number, since 2×66236621² = 8774579922995282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66236627) 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, 3010745 + ... + 3010766.

It is an arithmetic number, because the mean of its divisors is an integer number (18064536).

Almost surely, 2^66236621 is an apocalyptic number.

It is an amenable number.

66236621 is a deficient number, since it is larger than the sum of its proper divisors (6021523).

66236621 is a wasteful number, since it uses less digits than its factorization.

66236621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6021522.

The product of its digits is 15552, while the sum is 32.

The square root of 66236621 is about 8138.5883911155. The cubic root of 66236621 is about 404.6063766900.

Adding to 66236621 its reverse (12663266), we get a palindrome (78899887).

The spelling of 66236621 in words is "sixty-six million, two hundred thirty-six thousand, six hundred twenty-one".