20621918 has 8 divisors (see below), whose sum is σ = 32752512. Its totient is φ = 9704416.

The previous prime is 20621917. The next prime is 20621921. The reversal of 20621918 is 81912602.

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 (20621917) 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, 303230 + ... + 303297.

It is an arithmetic number, because the mean of its divisors is an integer number (4094064).

Almost surely, 2^20621918 is an apocalyptic number.

20621918 is a deficient number, since it is larger than the sum of its proper divisors (12130594).

20621918 is a wasteful number, since it uses less digits than its factorization.

20621918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606546.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 20621918 is about 4541.1362014368. The cubic root of 20621918 is about 274.2266670028.

The spelling of 20621918 in words is "twenty million, six hundred twenty-one thousand, nine hundred eighteen".