138940890 has 32 divisors (see below), whose sum is σ = 363773376. Its totient is φ = 33682560.

The previous prime is 138940889. The next prime is 138940897. The reversal of 138940890 is 98049831.

It is not an unprimeable number, because it can be changed into a prime (138940897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 210187 + ... + 210846.

It is an arithmetic number, because the mean of its divisors is an integer number (11367918).

Almost surely, 2^138940890 is an apocalyptic number.

138940890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138940890 is an abundant number, since it is smaller than the sum of its proper divisors (224832486).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138940890 is a wasteful number, since it uses less digits than its factorization.

138940890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421054.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 138940890 is about 11787.3190336056. The cubic root of 138940890 is about 517.9367080782.

The spelling of 138940890 in words is "one hundred thirty-eight million, nine hundred forty thousand, eight hundred ninety".