19975561 has 8 divisors (see below), whose sum is σ = 21205800. Its totient is φ = 18751488.

The previous prime is 19975547. The next prime is 19975601. The reversal of 19975561 is 16557991.

It can be written as a sum of positive squares in 4 ways, for example, as 12467961 + 7507600 = 3531^2 + 2740^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19975561 - 2⁷ = 19975433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19975531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6325 + ... + 8941.

It is an arithmetic number, because the mean of its divisors is an integer number (2650725).

Almost surely, 2^19975561 is an apocalyptic number.

It is an amenable number.

19975561 is a deficient number, since it is larger than the sum of its proper divisors (1230239).

19975561 is a wasteful number, since it uses less digits than its factorization.

19975561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3083.

The product of its digits is 85050, while the sum is 43.

The square root of 19975561 is about 4469.4027565213. The cubic root of 19975561 is about 271.3311538413.

The spelling of 19975561 in words is "nineteen million, nine hundred seventy-five thousand, five hundred sixty-one".