66954087257 has 4 divisors (see below), whose sum is σ = 70892562996.
Its totient is φ = 63015611520.
The previous prime is 66954087253. The next prime is 66954087287. The reversal of 66954087257 is 75278045966.
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 35054698441 + 31899388816 = 187229^2 + 178604^2
It is a cyclic number.
It is not a de Polignac number, because 66954087257 - 22 = 66954087253 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 66954087196 and 66954087205.
It is not an unprimeable number, because it can be changed into a prime (66954087253) 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, 1969237844 + ... + 1969237877.
It is an arithmetic number, because the mean of its divisors is an integer number (17723140749).
Almost surely, 266954087257 is an apocalyptic number.
It is an amenable number.
66954087257 is a deficient number, since it is larger than the sum of its proper divisors (3938475739).
66954087257 is a wasteful number, since it uses less digits than its factorization.
66954087257 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3938475738.
The product of its (nonzero) digits is 25401600, while the sum is 59.
The spelling of 66954087257 in words is "sixty-six billion, nine hundred fifty-four million, eighty-seven thousand, two hundred fifty-seven".