19636945 has 8 divisors (see below), whose sum is σ = 23588136. Its totient is φ = 15693696.

The previous prime is 19636943. The next prime is 19636949. The reversal of 19636945 is 54963691.

It can be written as a sum of positive squares in 4 ways, for example, as 5166529 + 14470416 = 2273^2 + 3804^2 .

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 19636945 - 2¹ = 19636943 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19636943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8539 + ... + 10591.

It is an arithmetic number, because the mean of its divisors is an integer number (2948517).

Almost surely, 2^19636945 is an apocalyptic number.

It is an amenable number.

19636945 is a deficient number, since it is larger than the sum of its proper divisors (3951191).

19636945 is a wasteful number, since it uses less digits than its factorization.

19636945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3971.

The product of its digits is 174960, while the sum is 43.

The square root of 19636945 is about 4431.3592722775. The cubic root of 19636945 is about 269.7892502645.

The spelling of 19636945 in words is "nineteen million, six hundred thirty-six thousand, nine hundred forty-five".