20319840 has 144 divisors (see below), whose sum is σ = 70525728. Its totient is φ = 5326848.

The previous prime is 20319823. The next prime is 20319853. The reversal of 20319840 is 4891302.

It is a tau number, because it is divible by the number of its divisors (144).

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, 148252 + ... + 148388.

It is an arithmetic number, because the mean of its divisors is an integer number (489762).

Almost surely, 2^20319840 is an apocalyptic number.

20319840 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 20319840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35262864).

20319840 is an abundant number, since it is smaller than the sum of its proper divisors (50205888).

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

20319840 is a wasteful number, since it uses less digits than its factorization.

20319840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20319840 is about 4507.7533206687. The cubic root of 20319840 is about 272.8810817254.

The spelling of 20319840 in words is "twenty million, three hundred nineteen thousand, eight hundred forty".