17921445420 has 48 divisors (see below), whose sum is σ = 50929014528. Its totient is φ = 4707721920.

The previous prime is 17921445413. The next prime is 17921445427. The reversal of 17921445420 is 2454412971.

It is an interprime number because it is at equal distance from previous prime (17921445413) and next prime (17921445427).

It is not an unprimeable number, because it can be changed into a prime (17921445427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2225016 + ... + 2233055.

It is an arithmetic number, because the mean of its divisors is an integer number (1061021136).

Almost surely, 2^17921445420 is an apocalyptic number.

17921445420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

17921445420 is an abundant number, since it is smaller than the sum of its proper divisors (33007569108).

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

17921445420 is a wasteful number, since it uses less digits than its factorization.

17921445420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4458150 (or 4458148 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The spelling of 17921445420 in words is "seventeen billion, nine hundred twenty-one million, four hundred forty-five thousand, four hundred twenty".