20690688 has 72 divisors (see below), whose sum is σ = 57027600. Its totient is φ = 6651904.

The previous prime is 20690687. The next prime is 20690689. The reversal of 20690688 is 88609602.

It is an interprime number because it is at equal distance from previous prime (20690687) and next prime (20690689).

It is a super-3 number, since 3×20690688³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20690687) 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, 21808 + ... + 22736.

It is an arithmetic number, because the mean of its divisors is an integer number (792050).

Almost surely, 2^20690688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20690688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28513800).

20690688 is an abundant number, since it is smaller than the sum of its proper divisors (36336912).

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

20690688 is an equidigital number, since it uses as much as digits as its factorization.

20690688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977 (or 963 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 20690688 is about 4548.7017928196. The cubic root of 20690688 is about 274.5311592659.

The spelling of 20690688 in words is "twenty million, six hundred ninety thousand, six hundred eighty-eight".