20817138 has 8 divisors (see below), whose sum is σ = 41634288. Its totient is φ = 6939044.

The previous prime is 20817133. The next prime is 20817143. The reversal of 20817138 is 83171802.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20817133) and next prime (20817143).

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

20817138 is an admirable number.

It is a super-2 number, since 2×20817138² = 866706469022088, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20817133) 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, 1734756 + ... + 1734767.

It is an arithmetic number, because the mean of its divisors is an integer number (5204286).

Almost surely, 2^20817138 is an apocalyptic number.

20817138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20817138 is a wasteful number, since it uses less digits than its factorization.

20817138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3469528.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 20817138 is about 4562.5801910761. The cubic root of 20817138 is about 275.0892845074.

The spelling of 20817138 in words is "twenty million, eight hundred seventeen thousand, one hundred thirty-eight".