66877621 has 4 divisors (see below), whose sum is σ = 68011200. Its totient is φ = 65744044.

The previous prime is 66877619. The next prime is 66877627. The reversal of 66877621 is 12677866.

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 66877621 - 2¹ = 66877619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66877627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 566701 + ... + 566818.

It is an arithmetic number, because the mean of its divisors is an integer number (17002800).

Almost surely, 2^66877621 is an apocalyptic number.

It is an amenable number.

66877621 is a deficient number, since it is larger than the sum of its proper divisors (1133579).

66877621 is a wasteful number, since it uses less digits than its factorization.

66877621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1133578.

The product of its digits is 169344, while the sum is 43.

The square root of 66877621 is about 8177.8738679439. The cubic root of 66877621 is about 405.9073716711.

The spelling of 66877621 in words is "sixty-six million, eight hundred seventy-seven thousand, six hundred twenty-one".