66276721 has 8 divisors (see below), whose sum is σ = 77356800. Its totient is φ = 55599648.

The previous prime is 66276713. The next prime is 66276733. The reversal of 66276721 is 12767266.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66276721 - 2³ = 66276713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66276781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100396 + ... + 101053.

It is an arithmetic number, because the mean of its divisors is an integer number (9669600).

Almost surely, 2^66276721 is an apocalyptic number.

It is an amenable number.

66276721 is a deficient number, since it is larger than the sum of its proper divisors (11080079).

66276721 is a wasteful number, since it uses less digits than its factorization.

66276721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201503.

The product of its digits is 42336, while the sum is 37.

The square root of 66276721 is about 8141.0515905502. The cubic root of 66276721 is about 404.6880104971.

The spelling of 66276721 in words is "sixty-six million, two hundred seventy-six thousand, seven hundred twenty-one".