20739456 has 128 divisors (see below), whose sum is σ = 64994400. Its totient is φ = 6488064.

The previous prime is 20739449. The next prime is 20739457. The reversal of 20739456 is 65493702.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20739456.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58576 + ... + 58928.

Almost surely, 2^20739456 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 20739456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32497200).

20739456 is an abundant number, since it is smaller than the sum of its proper divisors (44254944).

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

20739456 is a wasteful number, since it uses less digits than its factorization.

20739456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393 (or 375 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 20739456 is about 4554.0592881516. The cubic root of 20739456 is about 274.7466802215.

The spelling of 20739456 in words is "twenty million, seven hundred thirty-nine thousand, four hundred fifty-six".