138870646 has 4 divisors (see below), whose sum is σ = 208305972. Its totient is φ = 69435322.

The previous prime is 138870631. The next prime is 138870673. The reversal of 138870646 is 646078831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 646078831 = 19 ⋅34004149.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34717660 + ... + 34717663.

It is an arithmetic number, because the mean of its divisors is an integer number (52076493).

Almost surely, 2^138870646 is an apocalyptic number.

138870646 is a deficient number, since it is larger than the sum of its proper divisors (69435326).

138870646 is an equidigital number, since it uses as much as digits as its factorization.

138870646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69435325.

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 138870646 is about 11784.3390141323. The cubic root of 138870646 is about 517.8494093739.

The spelling of 138870646 in words is "one hundred thirty-eight million, eight hundred seventy thousand, six hundred forty-six".