66950010009 has 9 divisors (see below), whose sum is σ = 96706691263. Its totient is φ = 44632822512.

The previous prime is 66950009981. The next prime is 66950010059. The reversal of 66950010009 is 90001005966.

The square root of 66950010009 is 258747.

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

It can be written as a sum of positive squares in only one way, i.e., 65713784409 + 1236225600 = 256347^2 + 35160^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 66950010009 - 2⁷ = 66950009881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66950010059) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 733117 + ... + 819365.

Almost surely, 2^66950010009 is an apocalyptic number.

66950010009 is the 258747-th square number.

66950010009 is the 129374-th centered octagonal number.

It is an amenable number.

66950010009 is a deficient number, since it is larger than the sum of its proper divisors (29756681254).

66950010009 is an frugal number, since it uses more digits than its factorization.

66950010009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172504 (or 86252 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

Multiplying 66950010009 by its sum of digits (36), we get a square (2410200360324 = 1552482²).

The spelling of 66950010009 in words is "sixty-six billion, nine hundred fifty million, ten thousand, nine".