19998764541 has 64 divisors (see below), whose sum is σ = 34580121600. Its totient is φ = 11187082368.

The previous prime is 19998764519. The next prime is 19998764551. The reversal of 19998764541 is 14546789991.

19998764541 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 87 + 6 + 4 + 541 = 666.

It is not a de Polignac number, because 19998764541 - 2¹⁵ = 19998731773 is a prime.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19998764551) 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, 2059225 + ... + 2068913.

It is an arithmetic number, because the mean of its divisors is an integer number (540314400).

Almost surely, 2^19998764541 is an apocalyptic number.

It is an amenable number.

19998764541 is a deficient number, since it is larger than the sum of its proper divisors (14581357059).

19998764541 is a wasteful number, since it uses less digits than its factorization.

19998764541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9935 (or 9929 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 63.

The spelling of 19998764541 in words is "nineteen billion, nine hundred ninety-eight million, seven hundred sixty-four thousand, five hundred forty-one".