138841897 has 4 divisors (see below), whose sum is σ = 138948480. Its totient is φ = 138735316.

The previous prime is 138841891. The next prime is 138841921. The reversal of 138841897 is 798148831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 798148831 = 503 ⋅1586777.

It is a cyclic number.

It is not a de Polignac number, because 138841897 - 2¹⁹ = 138317609 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138841897.

It is not an unprimeable number, because it can be changed into a prime (138841891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51313 + ... + 53950.

It is an arithmetic number, because the mean of its divisors is an integer number (34737120).

Almost surely, 2^138841897 is an apocalyptic number.

It is an amenable number.

138841897 is a deficient number, since it is larger than the sum of its proper divisors (106583).

138841897 is a wasteful number, since it uses less digits than its factorization.

138841897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106582.

The product of its digits is 387072, while the sum is 49.

The square root of 138841897 is about 11783.1191541120. The cubic root of 138841897 is about 517.8136718475.

The spelling of 138841897 in words is "one hundred thirty-eight million, eight hundred forty-one thousand, eight hundred ninety-seven".