19817107957890 has 48 divisors (see below), whose sum is σ = 52250177618496. Its totient is φ = 5210131668000.

The previous prime is 19817107957877. The next prime is 19817107957891. The reversal of 19817107957890 is 9875970171891.

It is not an unprimeable number, because it can be changed into a prime (19817107957891) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1550628036 + ... + 1550640815.

It is an arithmetic number, because the mean of its divisors is an integer number (1088545367052).

Almost surely, 2^{19817107957890} is an apocalyptic number.

19817107957890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19817107957890 is an abundant number, since it is smaller than the sum of its proper divisors (32433069660606).

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

19817107957890 is a wasteful number, since it uses less digits than its factorization.

19817107957890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3101268935 (or 3101268932 counting only the distinct ones).

The product of its (nonzero) digits is 80015040, while the sum is 72.

The spelling of 19817107957890 in words is "nineteen trillion, eight hundred seventeen billion, one hundred seven million, nine hundred fifty-seven thousand, eight hundred ninety".