66897621 has 12 divisors (see below), whose sum is σ = 110434272. Its totient is φ = 38227176.

The previous prime is 66897587. The next prime is 66897629. The reversal of 66897621 is 12679866.

It is not a de Polignac number, because 66897621 - 2⁹ = 66897109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66897629) 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 11 ways as a sum of consecutive naturals, for example, 530871 + ... + 530996.

It is an arithmetic number, because the mean of its divisors is an integer number (9202856).

Almost surely, 2^66897621 is an apocalyptic number.

It is an amenable number.

66897621 is a deficient number, since it is larger than the sum of its proper divisors (43536651).

66897621 is a wasteful number, since it uses less digits than its factorization.

66897621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061880 (or 1061877 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 66897621 is about 8179.0965882547. The cubic root of 66897621 is about 405.9478303387.

It can be divided in two parts, 668 and 97621, that added together give a palindrome (98289).

The spelling of 66897621 in words is "sixty-six million, eight hundred ninety-seven thousand, six hundred twenty-one".