20959440 has 80 divisors (see below), whose sum is σ = 67817088. Its totient is φ = 5344768.

The previous prime is 20959429. The next prime is 20959459. The reversal of 20959440 is 4495902.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20959440² = 878596250227200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3622 + ... + 7418.

Almost surely, 2^20959440 is an apocalyptic number.

20959440 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 20959440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33908544).

20959440 is an abundant number, since it is smaller than the sum of its proper divisors (46857648).

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

20959440 is a wasteful number, since it uses less digits than its factorization.

20959440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3836 (or 3830 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20959440 is about 4578.1480972114. The cubic root of 20959440 is about 275.7146809944.

The spelling of 20959440 in words is "twenty million, nine hundred fifty-nine thousand, four hundred forty".