66351597631201 has 3 divisors (see below), whose sum is σ = 66351605776851. Its totient is φ = 66351589485552.

The previous prime is 66351597631169. The next prime is 66351597631217. The reversal of 66351597631201 is 10213679515366.

It is a happy number.

The square root of 66351597631201 is 8145649.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 4283041341601 + 62068556289600 = 2069551^2 + 7878360^2 .

It is not a de Polignac number, because 66351597631201 - 2⁵ = 66351597631169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66351597631261) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4072825 + ... + 12218473.

It is an arithmetic number, because the mean of its divisors is an integer number (22117201925617).

Almost surely, 2^{66351597631201} is an apocalyptic number.

66351597631201 is the 8145649-th square number.

66351597631201 is the 4072825-th centered octagonal number.

It is an amenable number.

66351597631201 is a deficient number, since it is larger than the sum of its proper divisors (8145650).

66351597631201 is an frugal number, since it uses more digits than its factorization.

66351597631201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16291298 (or 8145649 counting only the distinct ones).

The product of its (nonzero) digits is 6123600, while the sum is 55.

The spelling of 66351597631201 in words is "sixty-six trillion, three hundred fifty-one billion, five hundred ninety-seven million, six hundred thirty-one thousand, two hundred one".