138697861 has 4 divisors (see below), whose sum is σ = 140651424. Its totient is φ = 136744300.

The previous prime is 138697859. The next prime is 138697877. The reversal of 138697861 is 168796831.

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.

It is a cyclic number.

It is not a de Polignac number, because 138697861 - 2¹ = 138697859 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 (138694861) 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, 976675 + ... + 976816.

It is an arithmetic number, because the mean of its divisors is an integer number (35162856).

Almost surely, 2^138697861 is an apocalyptic number.

It is an amenable number.

138697861 is a deficient number, since it is larger than the sum of its proper divisors (1953563).

138697861 is an equidigital number, since it uses as much as digits as its factorization.

138697861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1953562.

The product of its digits is 435456, while the sum is 49.

The square root of 138697861 is about 11777.0056041423. The cubic root of 138697861 is about 517.6345481635.

The spelling of 138697861 in words is "one hundred thirty-eight million, six hundred ninety-seven thousand, eight hundred sixty-one".