66125921 has 4 divisors (see below), whose sum is σ = 67057344. Its totient is φ = 65194500.

The previous prime is 66125911. The next prime is 66125929. The reversal of 66125921 is 12952166.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-66125921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66125929) 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, 465605 + ... + 465746.

It is an arithmetic number, because the mean of its divisors is an integer number (16764336).

Almost surely, 2^66125921 is an apocalyptic number.

It is an amenable number.

66125921 is a deficient number, since it is larger than the sum of its proper divisors (931423).

66125921 is an equidigital number, since it uses as much as digits as its factorization.

66125921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 931422.

The product of its digits is 6480, while the sum is 32.

The square root of 66125921 is about 8131.7846134782. The cubic root of 66125921 is about 404.3808473650.

The spelling of 66125921 in words is "sixty-six million, one hundred twenty-five thousand, nine hundred twenty-one".