19493820 has 72 divisors (see below), whose sum is σ = 60750144. Its totient is φ = 5056128.

The previous prime is 19493807. The next prime is 19493821. The reversal of 19493820 is 2839491.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19493821) 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, 5197 + ... + 8123.

It is an arithmetic number, because the mean of its divisors is an integer number (843752).

Almost surely, 2^19493820 is an apocalyptic number.

19493820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19493820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30375072).

19493820 is an abundant number, since it is smaller than the sum of its proper divisors (41256324).

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

19493820 is a wasteful number, since it uses less digits than its factorization.

19493820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2979 (or 2974 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 19493820 is about 4415.1806305065. The cubic root of 19493820 is about 269.1321931949.

The spelling of 19493820 in words is "nineteen million, four hundred ninety-three thousand, eight hundred twenty".