138215957 has 8 divisors (see below), whose sum is σ = 151096512. Its totient is φ = 125388000.

The previous prime is 138215953. The next prime is 138215963. The reversal of 138215957 is 759512831.

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

It is a cyclic number.

It is not a de Polignac number, because 138215957 - 2² = 138215953 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 (138215953) 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, 7544 + ... + 18257.

It is an arithmetic number, because the mean of its divisors is an integer number (18887064).

Almost surely, 2^138215957 is an apocalyptic number.

It is an amenable number.

138215957 is a deficient number, since it is larger than the sum of its proper divisors (12880555).

138215957 is a wasteful number, since it uses less digits than its factorization.

138215957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26299.

The product of its digits is 75600, while the sum is 41.

The square root of 138215957 is about 11756.5282715604. The cubic root of 138215957 is about 517.0343475541.

The spelling of 138215957 in words is "one hundred thirty-eight million, two hundred fifteen thousand, nine hundred fifty-seven".