19409566842 has 40 divisors (see below), whose sum is σ = 46050155316. Its totient is φ = 6089275008.

The previous prime is 19409566837. The next prime is 19409566843. The reversal of 19409566842 is 24866590491.

It can be written as a sum of positive squares in 2 ways, for example, as 18958811481 + 450755361 = 137691^2 + 21231^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (19409566843) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3521133 + ... + 3526640.

Almost surely, 2^19409566842 is an apocalyptic number.

19409566842 is an abundant number, since it is smaller than the sum of its proper divisors (26640588474).

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

19409566842 is a wasteful number, since it uses less digits than its factorization.

19409566842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7047804 (or 7047795 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 19409566842 in words is "nineteen billion, four hundred nine million, five hundred sixty-six thousand, eight hundred forty-two".