138245890 has 16 divisors (see below), whose sum is σ = 249914808. Its totient is φ = 55060096.

The previous prime is 138245869. The next prime is 138245959. The reversal of 138245890 is 98542831.

It can be written as a sum of positive squares in 4 ways, for example, as 88416409 + 49829481 = 9403^2 + 7059^2 .

It is a super-2 number, since 2×138245890² = 38223852203784200, which contains 22 as substring.

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, 27337 + ... + 31996.

Almost surely, 2^138245890 is an apocalyptic number.

138245890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138245890 is a deficient number, since it is larger than the sum of its proper divisors (111668918).

138245890 is a wasteful number, since it uses less digits than its factorization.

138245890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59573.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 138245890 is about 11757.8012400278. The cubic root of 138245890 is about 517.0716690336.

The spelling of 138245890 in words is "one hundred thirty-eight million, two hundred forty-five thousand, eight hundred ninety".