138945825 has 18 divisors (see below), whose sum is σ = 248867814. Its totient is φ = 74104320.

The previous prime is 138945809. The next prime is 138945869. The reversal of 138945825 is 528549831.

It can be written as a sum of positive squares in 3 ways, for example, as 20223009 + 118722816 = 4497^2 + 10896^2 .

It is not a de Polignac number, because 138945825 - 2⁴ = 138945809 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 308544 + ... + 308993.

Almost surely, 2^138945825 is an apocalyptic number.

138945825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138945825 is a deficient number, since it is larger than the sum of its proper divisors (109921989).

138945825 is a wasteful number, since it uses less digits than its factorization.

138945825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617553 (or 617545 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 138945825 is about 11787.5283668800. The cubic root of 138945825 is about 517.9428401521.

The spelling of 138945825 in words is "one hundred thirty-eight million, nine hundred forty-five thousand, eight hundred twenty-five".