19621998 has 48 divisors (see below), whose sum is σ = 46843056. Its totient is φ = 5886720.

The previous prime is 19621969. The next prime is 19622021. The reversal of 19621998 is 89912691.

19621998 is a `hidden beast` number, since 19 + 621 + 9 + 9 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21936 + ... + 22812.

It is an arithmetic number, because the mean of its divisors is an integer number (975897).

Almost surely, 2^19621998 is an apocalyptic number.

19621998 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 19621998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23421528).

19621998 is an abundant number, since it is smaller than the sum of its proper divisors (27221058).

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

19621998 is a wasteful number, since it uses less digits than its factorization.

19621998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1009 (or 1006 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 19621998 is about 4429.6724483871. The cubic root of 19621998 is about 269.7207813062.

The spelling of 19621998 in words is "nineteen million, six hundred twenty-one thousand, nine hundred ninety-eight".