20214640 has 40 divisors (see below), whose sum is σ = 48153168. Its totient is φ = 7887360.

The previous prime is 20214611. The next prime is 20214647. The reversal of 20214640 is 4641202.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20214647) 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, 199 + ... + 6361.

Almost surely, 2^20214640 is an apocalyptic number.

20214640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20214640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24076584).

20214640 is an abundant number, since it is smaller than the sum of its proper divisors (27938528).

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

20214640 is a wasteful number, since it uses less digits than its factorization.

20214640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6217 (or 6211 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 20214640 is about 4496.0693944823. The cubic root of 20214640 is about 272.4093461602.

Adding to 20214640 its reverse (4641202), we get a palindrome (24855842).

The spelling of 20214640 in words is "twenty million, two hundred fourteen thousand, six hundred forty".