139810721 has 16 divisors (see below), whose sum is σ = 154122240. Its totient is φ = 126236880.

The previous prime is 139810717. The next prime is 139810747. The reversal of 139810721 is 127018931.

It is not a de Polignac number, because 139810721 - 2² = 139810717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (139810751) 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, 201986 + ... + 202676.

It is an arithmetic number, because the mean of its divisors is an integer number (9632640).

Almost surely, 2^139810721 is an apocalyptic number.

It is an amenable number.

139810721 is a deficient number, since it is larger than the sum of its proper divisors (14311519).

139810721 is a wasteful number, since it uses less digits than its factorization.

139810721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 139810721 is about 11824.1583632832. The cubic root of 139810721 is about 519.0152974826.

The spelling of 139810721 in words is "one hundred thirty-nine million, eight hundred ten thousand, seven hundred twenty-one".