138697424 has 40 divisors (see below), whose sum is σ = 291496968. Its totient is φ = 63672320.

The previous prime is 138697417. The next prime is 138697453. The reversal of 138697424 is 424796831.

It can be written as a sum of positive squares in 4 ways, for example, as 211600 + 138485824 = 460^2 + 11768^2 .

It is a congruent 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, 4934 + ... + 17370.

Almost surely, 2^138697424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138697424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145748484).

138697424 is an abundant number, since it is smaller than the sum of its proper divisors (152799544).

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

138697424 is a wasteful number, since it uses less digits than its factorization.

138697424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12503 (or 12497 counting only the distinct ones).

The product of its digits is 290304, while the sum is 44.

The square root of 138697424 is about 11776.9870510246. The cubic root of 138697424 is about 517.6340045201.

The spelling of 138697424 in words is "one hundred thirty-eight million, six hundred ninety-seven thousand, four hundred twenty-four".