138444770 has 16 divisors (see below), whose sum is σ = 263859768. Its totient is φ = 52120320.

The previous prime is 138444769. The next prime is 138444793. The reversal of 138444770 is 77444831.

It can be written as a sum of positive squares in 4 ways, for example, as 101344489 + 37100281 = 10067^2 + 6091^2 .

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 407021 + ... + 407360.

Almost surely, 2^138444770 is an apocalyptic number.

138444770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138444770 is a deficient number, since it is larger than the sum of its proper divisors (125414998).

138444770 is a wasteful number, since it uses less digits than its factorization.

138444770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814405.

The product of its (nonzero) digits is 75264, while the sum is 38.

The square root of 138444770 is about 11766.2555641121. The cubic root of 138444770 is about 517.3195026585.

The spelling of 138444770 in words is "one hundred thirty-eight million, four hundred forty-four thousand, seven hundred seventy".