20933640 has 320 divisors, whose sum is σ = 87816960. Its totient is φ = 4354560.

The previous prime is 20933639. The next prime is 20933641. The reversal of 20933640 is 4633902.

It is an interprime number because it is at equal distance from previous prime (20933639) and next prime (20933641).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20933641) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 294805 + ... + 294875.

It is an arithmetic number, because the mean of its divisors is an integer number (274428).

Almost surely, 2^20933640 is an apocalyptic number.

20933640 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 20933640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43908480).

20933640 is an abundant number, since it is smaller than the sum of its proper divisors (66883320).

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

20933640 is a wasteful number, since it uses less digits than its factorization.

20933640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 20933640 is about 4575.3294963314. The cubic root of 20933640 is about 275.6015043140.

The spelling of 20933640 in words is "twenty million, nine hundred thirty-three thousand, six hundred forty".