138897771 has 16 divisors (see below), whose sum is σ = 196035840. Its totient is φ = 87233760.

The previous prime is 138897751. The next prime is 138897779. The reversal of 138897771 is 177798831.

It is a happy number.

138897771 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138897771 - 2²⁷ = 4680043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138897779) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3586 + ... + 17048.

It is an arithmetic number, because the mean of its divisors is an integer number (12252240).

Almost surely, 2^138897771 is an apocalyptic number.

138897771 is a deficient number, since it is larger than the sum of its proper divisors (57138069).

138897771 is a wasteful number, since it uses less digits than its factorization.

138897771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13666.

The product of its digits is 592704, while the sum is 51.

The square root of 138897771 is about 11785.4898498111. The cubic root of 138897771 is about 517.8831236041.

The spelling of 138897771 in words is "one hundred thirty-eight million, eight hundred ninety-seven thousand, seven hundred seventy-one".