20544787998 has 80 divisors (see below), whose sum is σ = 52844482944. Its totient is φ = 5844007440.

The previous prime is 20544787993. The next prime is 20544788021. The reversal of 20544787998 is 89978744502.

20544787998 is a `hidden beast` number, since 2 + 0 + 5 + 4 + 478 + 79 + 98 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20544787993) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 217513 + ... + 297323.

Almost surely, 2^20544787998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20544787998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26422241472).

20544787998 is an abundant number, since it is smaller than the sum of its proper divisors (32299694946).

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

20544787998 is a wasteful number, since it uses less digits than its factorization.

20544787998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80059 (or 80050 counting only the distinct ones).

The product of its (nonzero) digits is 40642560, while the sum is 63.

The spelling of 20544787998 in words is "twenty billion, five hundred forty-four million, seven hundred eighty-seven thousand, nine hundred ninety-eight".