138949785 has 72 divisors (see below), whose sum is σ = 271744200. Its totient is φ = 65286144.

The previous prime is 138949753. The next prime is 138949807. The reversal of 138949785 is 587949831.

It can be written as a sum of positive squares in 4 ways, for example, as 4575321 + 134374464 = 2139^2 + 11592^2 .

It is not a de Polignac number, because 138949785 - 2⁵ = 138949753 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 309241 + ... + 309689.

It is an arithmetic number, because the mean of its divisors is an integer number (3774225).

Almost surely, 2^138949785 is an apocalyptic number.

138949785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138949785 is a deficient number, since it is larger than the sum of its proper divisors (132794415).

138949785 is a wasteful number, since it uses less digits than its factorization.

138949785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 493 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 138949785 is about 11787.6963398282. The cubic root of 138949785 is about 517.9477606170.

The spelling of 138949785 in words is "one hundred thirty-eight million, nine hundred forty-nine thousand, seven hundred eighty-five".