19138644 has 72 divisors (see below), whose sum is σ = 55735680. Its totient is φ = 5424192.

The previous prime is 19138631. The next prime is 19138661. The reversal of 19138644 is 44683191.

19138644 is a `hidden beast` number, since 1 + 9 + 1 + 3 + 8 + 644 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 19138599 and 19138608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43377 + ... + 43815.

Almost surely, 2^19138644 is an apocalyptic number.

19138644 is a gapful number since it is divisible by the number (14) 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 19138644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27867840).

19138644 is an abundant number, since it is smaller than the sum of its proper divisors (36597036).

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

19138644 is a wasteful number, since it uses less digits than its factorization.

19138644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629 (or 624 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 19138644 is about 4374.7735941418. The cubic root of 19138644 is about 267.4876414356.

The spelling of 19138644 in words is "nineteen million, one hundred thirty-eight thousand, six hundred forty-four".