20287799889840 has 2560 divisors, whose sum is σ = 90734558330880. Its totient is φ = 4058284032000.

The previous prime is 20287799889827. The next prime is 20287799889859. The reversal of 20287799889840 is 4898899778202.

It is a super-2 number, since 2×20287799889840² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20287799889840.

It is an unprimeable number.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 36423338842 + ... + 36423339398.

It is an arithmetic number, because the mean of its divisors is an integer number (35443186848).

Almost surely, 2^{20287799889840} is an apocalyptic number.

20287799889840 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 20287799889840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45367279165440).

20287799889840 is an abundant number, since it is smaller than the sum of its proper divisors (70446758441040).

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

20287799889840 is a wasteful number, since it uses less digits than its factorization.

20287799889840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 788 (or 776 counting only the distinct ones).

The product of its (nonzero) digits is 2341011456, while the sum is 81.

The spelling of 20287799889840 in words is "twenty trillion, two hundred eighty-seven billion, seven hundred ninety-nine million, eight hundred eighty-nine thousand, eight hundred forty".