19790561 has 6 divisors (see below), whose sum is σ = 23021730. Its totient is φ = 16963296.

The previous prime is 19790543. The next prime is 19790569. The reversal of 19790561 is 16509791.

It can be written as a sum of positive squares in only one way, i.e., 18113536 + 1677025 = 4256^2 + 1295^2 .

It is not a de Polignac number, because 19790561 - 2⁶ = 19790497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19790569) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 201896 + ... + 201993.

It is an arithmetic number, because the mean of its divisors is an integer number (3836955).

Almost surely, 2^19790561 is an apocalyptic number.

It is an amenable number.

19790561 is a deficient number, since it is larger than the sum of its proper divisors (3231169).

19790561 is an equidigital number, since it uses as much as digits as its factorization.

19790561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403903 (or 403896 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 19790561 is about 4448.6583370720. The cubic root of 19790561 is about 270.4909266776.

The spelling of 19790561 in words is "nineteen million, seven hundred ninety thousand, five hundred sixty-one".