20681244 has 36 divisors (see below), whose sum is σ = 54216344. Its totient is φ = 6893424.

The previous prime is 20681239. The next prime is 20681249. The reversal of 20681244 is 44218602.

It is an interprime number because it is at equal distance from previous prime (20681239) and next prime (20681249).

It is a tau number, because it is divible by the number of its divisors (36).

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 (20681249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9667 + ... + 11610.

Almost surely, 2^20681244 is an apocalyptic number.

It is an amenable number.

20681244 is an abundant number, since it is smaller than the sum of its proper divisors (33535100).

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

20681244 is a wasteful number, since it uses less digits than its factorization.

20681244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21296 (or 21282 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 20681244 is about 4547.6635759475. The cubic root of 20681244 is about 274.4893841635.

Adding to 20681244 its reverse (44218602), we get a palindrome (64899846).

The spelling of 20681244 in words is "twenty million, six hundred eighty-one thousand, two hundred forty-four".