137638921 has 8 divisors (see below), whose sum is σ = 157386944. Its totient is φ = 117912240.

The previous prime is 137638913. The next prime is 137638939. The reversal of 137638921 is 129836731.

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 137638921 - 2³ = 137638913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137638951) 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, 12451 + ... + 20743.

It is an arithmetic number, because the mean of its divisors is an integer number (19673368).

Almost surely, 2^137638921 is an apocalyptic number.

It is an amenable number.

137638921 is a deficient number, since it is larger than the sum of its proper divisors (19748023).

137638921 is an equidigital number, since it uses as much as digits as its factorization.

137638921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10671.

The product of its digits is 54432, while the sum is 40.

The square root of 137638921 is about 11731.9615154500. The cubic root of 137638921 is about 516.3138239309.

The spelling of 137638921 in words is "one hundred thirty-seven million, six hundred thirty-eight thousand, nine hundred twenty-one".