138897538 has 16 divisors (see below), whose sum is σ = 227449656. Its totient is φ = 63227520.

The previous prime is 138897533. The next prime is 138897541. The reversal of 138897538 is 835798831.

It can be written as a sum of positive squares in 4 ways, for example, as 84033889 + 54863649 = 9167^2 + 7407^2 .

It is a super-2 number, since 2×138897538² = 38585052124922888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138897533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34693 + ... + 38488.

Almost surely, 2^138897538 is an apocalyptic number.

138897538 is a deficient number, since it is larger than the sum of its proper divisors (88552118).

138897538 is a wasteful number, since it uses less digits than its factorization.

138897538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73269.

The product of its digits is 1451520, while the sum is 52.

The square root of 138897538 is about 11785.4799647702. The cubic root of 138897538 is about 517.8828340222.

The spelling of 138897538 in words is "one hundred thirty-eight million, eight hundred ninety-seven thousand, five hundred thirty-eight".