66220051897 has 4 divisors (see below), whose sum is σ = 67835175156. Its totient is φ = 64604928640.

The previous prime is 66220051883. The next prime is 66220051949. The reversal of 66220051897 is 79815002266.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1427403961 + 64792647936 = 37781^2 + 254544^2 .

It is a cyclic number.

It is not a de Polignac number, because 66220051897 - 2²⁷ = 66085834169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66220051697) 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, 807561568 + ... + 807561649.

It is an arithmetic number, because the mean of its divisors is an integer number (16958793789).

Almost surely, 2^66220051897 is an apocalyptic number.

It is an amenable number.

66220051897 is a deficient number, since it is larger than the sum of its proper divisors (1615123259).

66220051897 is a wasteful number, since it uses less digits than its factorization.

66220051897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615123258.

The product of its (nonzero) digits is 362880, while the sum is 46.

The spelling of 66220051897 in words is "sixty-six billion, two hundred twenty million, fifty-one thousand, eight hundred ninety-seven".