66110621 has 4 divisors (see below), whose sum is σ = 67231200. Its totient is φ = 64990044.

The previous prime is 66110587. The next prime is 66110647. The reversal of 66110621 is 12601166.

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 a cyclic number.

It is not a de Polignac number, because 66110621 - 2¹⁸ = 65848477 is a prime.

It is a super-2 number, since 2×66110621² = 8741228418011282, 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 (66110021) 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, 560201 + ... + 560318.

It is an arithmetic number, because the mean of its divisors is an integer number (16807800).

Almost surely, 2^66110621 is an apocalyptic number.

It is an amenable number.

66110621 is a deficient number, since it is larger than the sum of its proper divisors (1120579).

66110621 is a wasteful number, since it uses less digits than its factorization.

66110621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120578.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 66110621 is about 8130.8438061495. The cubic root of 66110621 is about 404.3496568519.

Adding to 66110621 its reverse (12601166), we get a palindrome (78711787).

The spelling of 66110621 in words is "sixty-six million, one hundred ten thousand, six hundred twenty-one".