20218388 has 12 divisors (see below), whose sum is σ = 35518560. Its totient is φ = 10070232.

The previous prime is 20218381. The next prime is 20218411. The reversal of 20218388 is 88381202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20218381) 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, 8558 + ... + 10661.

It is an arithmetic number, because the mean of its divisors is an integer number (2959880).

Almost surely, 2^20218388 is an apocalyptic number.

It is an amenable number.

20218388 is a deficient number, since it is larger than the sum of its proper divisors (15300172).

20218388 is a wasteful number, since it uses less digits than its factorization.

20218388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19486 (or 19484 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 20218388 is about 4496.4861836772. The cubic root of 20218388 is about 272.4261809416.

The spelling of 20218388 in words is "twenty million, two hundred eighteen thousand, three hundred eighty-eight".