139090721 has 8 divisors (see below), whose sum is σ = 173411904. Its totient is φ = 108382320.

The previous prime is 139090703. The next prime is 139090741. The reversal of 139090721 is 127090931.

It is a happy number.

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 139090721 - 2⁶ = 139090657 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 (139090741) 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 7 ways as a sum of consecutive naturals, for example, 903110 + ... + 903263.

It is an arithmetic number, because the mean of its divisors is an integer number (21676488).

Almost surely, 2^139090721 is an apocalyptic number.

139090721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

139090721 is a deficient number, since it is larger than the sum of its proper divisors (34321183).

139090721 is a wasteful number, since it uses less digits than its factorization.

139090721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1806391.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 139090721 is about 11793.6729223766. The cubic root of 139090721 is about 518.1228186284.

The spelling of 139090721 in words is "one hundred thirty-nine million, ninety thousand, seven hundred twenty-one".