20499013440 has 448 divisors, whose sum is σ = 77560139520. Its totient is φ = 5141864448.

The previous prime is 20499013433. The next prime is 20499013441. The reversal of 20499013440 is 4431099402.

20499013440 is a `hidden beast` number, since 204 + 9 + 9 + 0 + 1 + 3 + 440 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 20499013395 and 20499013404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20499013441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11896419 + ... + 11898141.

Almost surely, 2^20499013440 is an apocalyptic number.

20499013440 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 20499013440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38780069760).

20499013440 is an abundant number, since it is smaller than the sum of its proper divisors (57061126080).

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

20499013440 is an equidigital number, since it uses as much as digits as its factorization.

20499013440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1778 (or 1750 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 20499013440 in words is "twenty billion, four hundred ninety-nine million, thirteen thousand, four hundred forty".