20786988 has 96 divisors (see below), whose sum is σ = 56125440. Its totient is φ = 5944320.

The previous prime is 20786981. The next prime is 20787001. The reversal of 20786988 is 88968702.

It is a happy number.

It is a super-2 number, since 2×20786988² = 864197740224288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20786981) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 120070 + ... + 120242.

It is an arithmetic number, because the mean of its divisors is an integer number (584640).

Almost surely, 2^20786988 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 20786988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28062720).

20786988 is an abundant number, since it is smaller than the sum of its proper divisors (35338452).

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

20786988 is a wasteful number, since it uses less digits than its factorization.

20786988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 245 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 48.

The square root of 20786988 is about 4559.2749423565. The cubic root of 20786988 is about 274.9564140289.

The spelling of 20786988 in words is "twenty million, seven hundred eighty-six thousand, nine hundred eighty-eight".