19855420 has 24 divisors (see below), whose sum is σ = 44904384. Its totient is φ = 7331136.

The previous prime is 19855391. The next prime is 19855427. The reversal of 19855420 is 2455891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19855427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37924 + ... + 38443.

It is an arithmetic number, because the mean of its divisors is an integer number (1871016).

Almost surely, 2^19855420 is an apocalyptic number.

19855420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19855420 is an abundant number, since it is smaller than the sum of its proper divisors (25048964).

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

19855420 is a wasteful number, since it uses less digits than its factorization.

19855420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76389 (or 76387 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 19855420 is about 4455.9421001624. The cubic root of 19855420 is about 270.7860950091.

The spelling of 19855420 in words is "nineteen million, eight hundred fifty-five thousand, four hundred twenty".