139243993 has 16 divisors (see below), whose sum is σ = 166959360. Its totient is φ = 113601600.

The previous prime is 139243969. The next prime is 139243999. The reversal of 139243993 is 399342931.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-139243993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139243999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9583 + ... + 19243.

It is an arithmetic number, because the mean of its divisors is an integer number (10434960).

Almost surely, 2^139243993 is an apocalyptic number.

It is an amenable number.

139243993 is a deficient number, since it is larger than the sum of its proper divisors (27715367).

139243993 is an equidigital number, since it uses as much as digits as its factorization.

139243993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9768.

The product of its digits is 157464, while the sum is 43.

The square root of 139243993 is about 11800.1691937023. The cubic root of 139243993 is about 518.3130651279.

The spelling of 139243993 in words is "one hundred thirty-nine million, two hundred forty-three thousand, nine hundred ninety-three".