66392645281 has 16 divisors (see below), whose sum is σ = 68004147456. Its totient is φ = 64800000000.

The previous prime is 66392645239. The next prime is 66392645311. The reversal of 66392645281 is 18254629366.

It is a 8-Lehmer number, since φ(66392645281) divides (66392645281-1)⁸.

It is a cyclic number.

It is not a de Polignac number, because 66392645281 - 2²¹ = 66390548129 is a prime.

It is a super-2 number, since 2×66392645281² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66392645381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4141281 + ... + 4157281.

It is an arithmetic number, because the mean of its divisors is an integer number (4250259216).

Almost surely, 2^66392645281 is an apocalyptic number.

66392645281 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

66392645281 is the 115233-rd centered decagonal number.

It is an amenable number.

66392645281 is a deficient number, since it is larger than the sum of its proper divisors (1611502175).

66392645281 is a wasteful number, since it uses less digits than its factorization.

66392645281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16584.

The product of its digits is 3732480, while the sum is 52.

The spelling of 66392645281 in words is "sixty-six billion, three hundred ninety-two million, six hundred forty-five thousand, two hundred eighty-one".