181666857535390 has 16 divisors (see below), whose sum is σ = 327466820528640. Its totient is φ = 72563081466400.

The previous prime is 181666857535381. The next prime is 181666857535391. The reversal of 181666857535390 is 93535758666181.

181666857535390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181666857535391) 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, 12957686110 + ... + 12957700129.

It is an arithmetic number, because the mean of its divisors is an integer number (20466676283040).

Almost surely, 2^{181666857535390} is an apocalyptic number.

181666857535390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

181666857535390 is a deficient number, since it is larger than the sum of its proper divisors (145799962993250).

181666857535390 is a wasteful number, since it uses less digits than its factorization.

181666857535390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25915386947.

The product of its (nonzero) digits is 979776000, while the sum is 73.

The spelling of 181666857535390 in words is "one hundred eighty-one trillion, six hundred sixty-six billion, eight hundred fifty-seven million, five hundred thirty-five thousand, three hundred ninety".