66670721998201 has 4 divisors (see below), whose sum is σ = 66673245232512. Its totient is φ = 66668198763892.

The previous prime is 66670721998193. The next prime is 66670721998271. The reversal of 66670721998201 is 10289912707666.

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 66670721998201 - 2³ = 66670721998193 is a prime.

It is a super-2 number, since 2×66670721998201² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66670721998271) 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, 1261577521 + ... + 1261630366.

It is an arithmetic number, because the mean of its divisors is an integer number (16668311308128).

Almost surely, 2^{66670721998201} is an apocalyptic number.

It is an amenable number.

66670721998201 is a deficient number, since it is larger than the sum of its proper divisors (2523234311).

66670721998201 is a wasteful number, since it uses less digits than its factorization.

66670721998201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2523234310.

The product of its (nonzero) digits is 27433728, while the sum is 64.

The spelling of 66670721998201 in words is "sixty-six trillion, six hundred seventy billion, seven hundred twenty-one million, nine hundred ninety-eight thousand, two hundred one".