138988730 has 16 divisors (see below), whose sum is σ = 250443144. Its totient is φ = 55536960.

The previous prime is 138988723. The next prime is 138988813. The reversal of 138988730 is 37889831.

It can be written as a sum of positive squares in 4 ways, for example, as 66210769 + 72777961 = 8137^2 + 8531^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3404 + ... + 17016.

Almost surely, 2^138988730 is an apocalyptic number.

138988730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138988730 is a deficient number, since it is larger than the sum of its proper divisors (111454414).

138988730 is a wasteful number, since it uses less digits than its factorization.

138988730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14641.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 138988730 is about 11789.3481584013. The cubic root of 138988730 is about 517.9961464211.

The spelling of 138988730 in words is "one hundred thirty-eight million, nine hundred eighty-eight thousand, seven hundred thirty".