19908949518 has 96 divisors (see below), whose sum is σ = 46079953920. Its totient is φ = 6201740160.

The previous prime is 19908949507. The next prime is 19908949553. The reversal of 19908949518 is 81594980991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2130805 + ... + 2140127.

It is an arithmetic number, because the mean of its divisors is an integer number (479999520).

Almost surely, 2^19908949518 is an apocalyptic number.

19908949518 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19908949518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23039976960).

19908949518 is an abundant number, since it is smaller than the sum of its proper divisors (26171004402).

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

19908949518 is a wasteful number, since it uses less digits than its factorization.

19908949518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9494 (or 9491 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 63.

The spelling of 19908949518 in words is "nineteen billion, nine hundred eight million, nine hundred forty-nine thousand, five hundred eighteen".