20739440 has 40 divisors (see below), whose sum is σ = 49403088. Its totient is φ = 8092160.

The previous prime is 20739427. The next prime is 20739449. The reversal of 20739440 is 4493702.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119 + ... + 6441.

Almost surely, 2^20739440 is an apocalyptic number.

20739440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20739440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24701544).

20739440 is an abundant number, since it is smaller than the sum of its proper divisors (28663648).

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

20739440 is a wasteful number, since it uses less digits than its factorization.

20739440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6377 (or 6371 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20739440 is about 4554.0575314767. The cubic root of 20739440 is about 274.7466095680.

The spelling of 20739440 in words is "twenty million, seven hundred thirty-nine thousand, four hundred forty".