20349987840 has 1056 divisors, whose sum is σ = 90986628096. Its totient is φ = 4087480320.

The previous prime is 20349987799. The next prime is 20349987841. The reversal of 20349987840 is 4878994302.

It is a super-3 number, since 3×20349987840³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20349987841) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 96445335 + ... + 96445545.

Almost surely, 2^20349987840 is an apocalyptic number.

20349987840 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 20349987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45493314048).

20349987840 is an abundant number, since it is smaller than the sum of its proper divisors (70636640256).

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

20349987840 is a wasteful number, since it uses less digits than its factorization.

20349987840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 20349987840 in words is "twenty billion, three hundred forty-nine million, nine hundred eighty-seven thousand, eight hundred forty".