20897518 has 8 divisors (see below), whose sum is σ = 31365720. Its totient is φ = 10442280.

The previous prime is 20897509. The next prime is 20897519. The reversal of 20897518 is 81579802.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897519) 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, 4308 + ... + 7768.

It is an arithmetic number, because the mean of its divisors is an integer number (3920715).

Almost surely, 2^20897518 is an apocalyptic number.

20897518 is a deficient number, since it is larger than the sum of its proper divisors (10468202).

20897518 is a wasteful number, since it uses less digits than its factorization.

20897518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6482.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 20897518 is about 4571.3803167096. The cubic root of 20897518 is about 275.4428918424.

The spelling of 20897518 in words is "twenty million, eight hundred ninety-seven thousand, five hundred eighteen".