19792561 has 4 divisors (see below), whose sum is σ = 19826532. Its totient is φ = 19758592.

The previous prime is 19792541. The next prime is 19792571. The reversal of 19792561 is 16529791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16529791 = 19 ⋅869989.

It can be written as a sum of positive squares in 2 ways, for example, as 13366336 + 6426225 = 3656^2 + 2535^2 .

It is a cyclic number.

It is not a de Polignac number, because 19792561 - 2⁹ = 19792049 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19792501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16096 + ... + 17281.

It is an arithmetic number, because the mean of its divisors is an integer number (4956633).

Almost surely, 2^19792561 is an apocalyptic number.

It is an amenable number.

19792561 is a deficient number, since it is larger than the sum of its proper divisors (33971).

19792561 is an equidigital number, since it uses as much as digits as its factorization.

19792561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33970.

The product of its digits is 34020, while the sum is 40.

The square root of 19792561 is about 4448.8831182669. The cubic root of 19792561 is about 270.5000381530.

The spelling of 19792561 in words is "nineteen million, seven hundred ninety-two thousand, five hundred sixty-one".