66921207 has 8 divisors (see below), whose sum is σ = 89462784. Its totient is φ = 44496888.

The previous prime is 66921203. The next prime is 66921221. The reversal of 66921207 is 70212966.

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

It is not a de Polignac number, because 66921207 - 2² = 66921203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66921203) 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, 27973 + ... + 30270.

It is an arithmetic number, because the mean of its divisors is an integer number (11182848).

Almost surely, 2^66921207 is an apocalyptic number.

66921207 is a deficient number, since it is larger than the sum of its proper divisors (22541577).

66921207 is a wasteful number, since it uses less digits than its factorization.

66921207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58629.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 66921207 is about 8180.5383074710. The cubic root of 66921207 is about 405.9955328846.

The spelling of 66921207 in words is "sixty-six million, nine hundred twenty-one thousand, two hundred seven".