139643923 has 4 divisors (see below), whose sum is σ = 142278768. Its totient is φ = 137009080.

The previous prime is 139643891. The next prime is 139643941. The reversal of 139643923 is 329346931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329346931 = 19 ⋅17334049.

It is a cyclic number.

It is not a de Polignac number, because 139643923 - 2⁵ = 139643891 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139643123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1317343 + ... + 1317448.

It is an arithmetic number, because the mean of its divisors is an integer number (35569692).

Almost surely, 2^139643923 is an apocalyptic number.

139643923 is a deficient number, since it is larger than the sum of its proper divisors (2634845).

139643923 is an equidigital number, since it uses as much as digits as its factorization.

139643923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2634844.

The product of its digits is 104976, while the sum is 40.

The square root of 139643923 is about 11817.1029867730. The cubic root of 139643923 is about 518.8088155503.

The spelling of 139643923 in words is "one hundred thirty-nine million, six hundred forty-three thousand, nine hundred twenty-three".