138356691 has 8 divisors (see below), whose sum is σ = 201246144. Its totient is φ = 83852520.

The previous prime is 138356683. The next prime is 138356737. The reversal of 138356691 is 196653831.

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 138356691 - 2³ = 138356683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138352691) 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, 2096281 + ... + 2096346.

It is an arithmetic number, because the mean of its divisors is an integer number (25155768).

Almost surely, 2^138356691 is an apocalyptic number.

138356691 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138356691 is a deficient number, since it is larger than the sum of its proper divisors (62889453).

138356691 is a wasteful number, since it uses less digits than its factorization.

138356691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4192641.

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

The square root of 138356691 is about 11762.5121041383. The cubic root of 138356691 is about 517.2097726178.

The spelling of 138356691 in words is "one hundred thirty-eight million, three hundred fifty-six thousand, six hundred ninety-one".