66253202765221 has 8 divisors (see below), whose sum is σ = 66273490819800. Its totient is φ = 66232915342848.

The previous prime is 66253202765219. The next prime is 66253202765261. The reversal of 66253202765221 is 12256720235266.

It can be written as a sum of positive squares in 4 ways, for example, as 270301209025 + 65982901556196 = 519905^2 + 8122986^2 .

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 66253202765221 - 2¹ = 66253202765219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66253202765261) 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, 289660315 + ... + 289888951.

It is an arithmetic number, because the mean of its divisors is an integer number (8284186352475).

Almost surely, 2^{66253202765221} is an apocalyptic number.

It is an amenable number.

66253202765221 is a deficient number, since it is larger than the sum of its proper divisors (20288054579).

66253202765221 is a wasteful number, since it uses less digits than its factorization.

66253202765221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316103.

The product of its (nonzero) digits is 3628800, while the sum is 49.

The spelling of 66253202765221 in words is "sixty-six trillion, two hundred fifty-three billion, two hundred two million, seven hundred sixty-five thousand, two hundred twenty-one".