66166463731 has 4 divisors (see below), whose sum is σ = 66167410312. Its totient is φ = 66165517152.

The previous prime is 66166463719. The next prime is 66166463777. The reversal of 66166463731 is 13736466166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13736466166 = 2 ⋅6868233083.

It is a cyclic number.

It is not a de Polignac number, because 66166463731 - 2¹⁵ = 66166430963 is a prime.

It is a super-2 number, since 2×66166463731² (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 (66166463431) 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, 359286 + ... + 511291.

It is an arithmetic number, because the mean of its divisors is an integer number (16541852578).

Almost surely, 2^66166463731 is an apocalyptic number.

66166463731 is a deficient number, since it is larger than the sum of its proper divisors (946581).

66166463731 is an equidigital number, since it uses as much as digits as its factorization.

66166463731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 946580.

The product of its digits is 1959552, while the sum is 49.

The spelling of 66166463731 in words is "sixty-six billion, one hundred sixty-six million, four hundred sixty-three thousand, seven hundred thirty-one".