19998764540 has 48 divisors (see below), whose sum is σ = 43392646080. Its totient is φ = 7737999360.

The previous prime is 19998764519. The next prime is 19998764551. The reversal of 19998764540 is 4546789991.

It is a super-2 number, since 2×19998764540² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57605 + ... + 208124.

It is an arithmetic number, because the mean of its divisors is an integer number (904013460).

Almost surely, 2^19998764540 is an apocalyptic number.

19998764540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19998764540 is an abundant number, since it is smaller than the sum of its proper divisors (23393881540).

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

19998764540 is a wasteful number, since it uses less digits than its factorization.

19998764540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265862 (or 265860 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 62.

The spelling of 19998764540 in words is "nineteen billion, nine hundred ninety-eight million, seven hundred sixty-four thousand, five hundred forty".