19921836 has 48 divisors (see below), whose sum is σ = 52093440. Its totient is φ = 5872320.

The previous prime is 19921831. The next prime is 19921877. The reversal of 19921836 is 63812991.

It is a super-2 number, since 2×19921836² = 793759099221792, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 19921794 and 19921803.

It is not an unprimeable number, because it can be changed into a prime (19921831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2845 + ... + 6923.

It is an arithmetic number, because the mean of its divisors is an integer number (1085280).

Almost surely, 2^19921836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19921836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26046720).

19921836 is an abundant number, since it is smaller than the sum of its proper divisors (32171604).

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

19921836 is a wasteful number, since it uses less digits than its factorization.

19921836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4134 (or 4132 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 19921836 is about 4463.3883989633. The cubic root of 19921836 is about 271.0876837580.

It can be divided in two parts, 1992 and 1836, that added together give a triangular number (3828 = T₈₇).

The spelling of 19921836 in words is "nineteen million, nine hundred twenty-one thousand, eight hundred thirty-six".