139666823 has 8 divisors (see below), whose sum is σ = 144761760. Its totient is φ = 134641440.

The previous prime is 139666801. The next prime is 139666837. The reversal of 139666823 is 328666931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139666823 - 2²⁰ = 138618247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139666223) 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, 13283 + ... + 21348.

It is an arithmetic number, because the mean of its divisors is an integer number (18095220).

Almost surely, 2^139666823 is an apocalyptic number.

139666823 is a deficient number, since it is larger than the sum of its proper divisors (5094937).

139666823 is a wasteful number, since it uses less digits than its factorization.

139666823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34777.

The product of its digits is 279936, while the sum is 44.

The square root of 139666823 is about 11818.0718816565. The cubic root of 139666823 is about 518.8371735632.

The spelling of 139666823 in words is "one hundred thirty-nine million, six hundred sixty-six thousand, eight hundred twenty-three".