19942566 has 32 divisors (see below), whose sum is σ = 45726720. Its totient is φ = 5679936.

The previous prime is 19942543. The next prime is 19942567. The reversal of 19942566 is 66524991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19942567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18675 + ... + 19713.

It is an arithmetic number, because the mean of its divisors is an integer number (1428960).

Almost surely, 2^19942566 is an apocalyptic number.

19942566 is an abundant number, since it is smaller than the sum of its proper divisors (25784154).

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

19942566 is a wasteful number, since it uses less digits than its factorization.

19942566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1508.

The product of its digits is 116640, while the sum is 42.

The square root of 19942566 is about 4465.7100219338. The cubic root of 19942566 is about 271.1816794387.

It can be divided in two parts, 1994 and 2566, that added together give a triangular number (4560 = T₉₅).

The spelling of 19942566 in words is "nineteen million, nine hundred forty-two thousand, five hundred sixty-six".