138440090 has 16 divisors (see below), whose sum is σ = 252912672. Its totient is φ = 54549264.

The previous prime is 138440089. The next prime is 138440147. The reversal of 138440090 is 90044831.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102644 + ... + 103983.

It is an arithmetic number, because the mean of its divisors is an integer number (15807042).

Almost surely, 2^138440090 is an apocalyptic number.

138440090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138440090 is a deficient number, since it is larger than the sum of its proper divisors (114472582).

138440090 is a wasteful number, since it uses less digits than its factorization.

138440090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206701.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 138440090 is about 11766.0566886277. The cubic root of 138440090 is about 517.3136734205.

The spelling of 138440090 in words is "one hundred thirty-eight million, four hundred forty thousand, ninety".