138563691 has 8 divisors (see below), whose sum is σ = 211144704. Its totient is φ = 79179240.

The previous prime is 138563687. The next prime is 138563699. The reversal of 138563691 is 196365831.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138563691 - 2² = 138563687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138563699) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3299115 + ... + 3299156.

It is an arithmetic number, because the mean of its divisors is an integer number (26393088).

Almost surely, 2^138563691 is an apocalyptic number.

138563691 is a deficient number, since it is larger than the sum of its proper divisors (72581013).

138563691 is an equidigital number, since it uses as much as digits as its factorization.

138563691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6598281.

The product of its digits is 116640, while the sum is 42.

The square root of 138563691 is about 11771.3079562129. The cubic root of 138563691 is about 517.4675822770.

The spelling of 138563691 in words is "one hundred thirty-eight million, five hundred sixty-three thousand, six hundred ninety-one".