138619897 has 4 divisors (see below), whose sum is σ = 149282980. Its totient is φ = 127956816.

The previous prime is 138619867. The next prime is 138619931. The reversal of 138619897 is 798916831.

It is a happy number.

138619897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 798916831 = 2377 ⋅336103.

It can be written as a sum of positive squares in 2 ways, for example, as 78340201 + 60279696 = 8851^2 + 7764^2 .

It is not a de Polignac number, because 138619897 - 2¹⁵ = 138587129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138619807) 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, 5331522 + ... + 5331547.

It is an arithmetic number, because the mean of its divisors is an integer number (37320745).

Almost surely, 2^138619897 is an apocalyptic number.

It is an amenable number.

138619897 is a deficient number, since it is larger than the sum of its proper divisors (10663083).

138619897 is a wasteful number, since it uses less digits than its factorization.

138619897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10663082.

The product of its digits is 653184, while the sum is 52.

The square root of 138619897 is about 11773.6951293976. The cubic root of 138619897 is about 517.5375401210.

The spelling of 138619897 in words is "one hundred thirty-eight million, six hundred nineteen thousand, eight hundred ninety-seven".