19944564 has 24 divisors (see below), whose sum is σ = 46763808. Its totient is φ = 6615840.

The previous prime is 19944559. The next prime is 19944569. The reversal of 19944564 is 46544991.

It is an interprime number because it is at equal distance from previous prime (19944559) and next prime (19944569).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19944569) 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, 1407 + ... + 6470.

It is an arithmetic number, because the mean of its divisors is an integer number (1948492).

Almost surely, 2^19944564 is an apocalyptic number.

It is an amenable number.

19944564 is an abundant number, since it is smaller than the sum of its proper divisors (26819244).

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

19944564 is a wasteful number, since it uses less digits than its factorization.

19944564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8095 (or 8093 counting only the distinct ones).

The product of its digits is 155520, while the sum is 42.

The square root of 19944564 is about 4465.9337209591. The cubic root of 19944564 is about 271.1907354933.

The spelling of 19944564 in words is "nineteen million, nine hundred forty-four thousand, five hundred sixty-four".