139245728 has 12 divisors (see below), whose sum is σ = 274140090. Its totient is φ = 69622848.

The previous prime is 139245727. The next prime is 139245761. The reversal of 139245728 is 827542931.

It can be written as a sum of positive squares in only one way, i.e., 134281744 + 4963984 = 11588^2 + 2228^2 .

It is not an unprimeable number, because it can be changed into a prime (139245727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2175683 + ... + 2175746.

Almost surely, 2^139245728 is an apocalyptic number.

It is an amenable number.

139245728 is a deficient number, since it is larger than the sum of its proper divisors (134894362).

139245728 is an equidigital number, since it uses as much as digits as its factorization.

139245728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4351439 (or 4351431 counting only the distinct ones).

The product of its digits is 120960, while the sum is 41.

The square root of 139245728 is about 11800.2427093683. The cubic root of 139245728 is about 518.3152178705.

The spelling of 139245728 in words is "one hundred thirty-nine million, two hundred forty-five thousand, seven hundred twenty-eight".