20981744 has 20 divisors (see below), whose sum is σ = 46459824. Its totient is φ = 8992128.

The previous prime is 20981711. The next prime is 20981747. The reversal of 20981744 is 44718902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20981747) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93557 + ... + 93780.

Almost surely, 2^20981744 is an apocalyptic number.

It is an amenable number.

20981744 is an abundant number, since it is smaller than the sum of its proper divisors (25478080).

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

20981744 is a wasteful number, since it uses less digits than its factorization.

20981744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187352 (or 187346 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20981744 is about 4580.5833689608. The cubic root of 20981744 is about 275.8124469682.

The spelling of 20981744 in words is "twenty million, nine hundred eighty-one thousand, seven hundred forty-four".