20469840 has 120 divisors (see below), whose sum is σ = 67808160. Its totient is φ = 5094144.

The previous prime is 20469829. The next prime is 20469851. The reversal of 20469840 is 4896402.

It is an interprime number because it is at equal distance from previous prime (20469829) and next prime (20469851).

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 305487 + ... + 305553.

It is an arithmetic number, because the mean of its divisors is an integer number (565068).

Almost surely, 2^20469840 is an apocalyptic number.

20469840 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 20469840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33904080).

20469840 is an abundant number, since it is smaller than the sum of its proper divisors (47338320).

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

20469840 is a wasteful number, since it uses less digits than its factorization.

20469840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20469840 is about 4524.3607283239. The cubic root of 20469840 is about 273.5509008710.

The spelling of 20469840 in words is "twenty million, four hundred sixty-nine thousand, eight hundred forty".