20717900 has 72 divisors (see below), whose sum is σ = 54434016. Its totient is φ = 6681600.

The previous prime is 20717897. The next prime is 20717903. The reversal of 20717900 is 971702.

It is an interprime number because it is at equal distance from previous prime (20717897) and next prime (20717903).

It is a self number, because there is not a number n which added to its sum of digits gives 20717900.

It is not an unprimeable number, because it can be changed into a prime (20717903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11030 + ... + 12770.

It is an arithmetic number, because the mean of its divisors is an integer number (756028).

Almost surely, 2^20717900 is an apocalyptic number.

20717900 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 20717900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27217008).

20717900 is an abundant number, since it is smaller than the sum of its proper divisors (33716116).

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

20717900 is a wasteful number, since it uses less digits than its factorization.

20717900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779 (or 1772 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 26.

The square root of 20717900 is about 4551.6919930944. The cubic root of 20717900 is about 274.6514592653.

The spelling of 20717900 in words is "twenty million, seven hundred seventeen thousand, nine hundred".