138123997 has 16 divisors (see below), whose sum is σ = 163864512. Its totient is φ = 114981120.

The previous prime is 138123967. The next prime is 138124001. The reversal of 138123997 is 799321831.

It is a cyclic number.

It is not a de Polignac number, because 138123997 - 2¹⁵ = 138091229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138123907) 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, 3063 + ... + 16900.

It is an arithmetic number, because the mean of its divisors is an integer number (10241532).

Almost surely, 2^138123997 is an apocalyptic number.

138123997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

138123997 is a deficient number, since it is larger than the sum of its proper divisors (25740515).

138123997 is a wasteful number, since it uses less digits than its factorization.

138123997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20028.

The product of its digits is 81648, while the sum is 43.

The square root of 138123997 is about 11752.6166022720. The cubic root of 138123997 is about 516.9196549906.

The spelling of 138123997 in words is "one hundred thirty-eight million, one hundred twenty-three thousand, nine hundred ninety-seven".