20645673 has 16 divisors (see below), whose sum is σ = 28740096. Its totient is φ = 13170560.

The previous prime is 20645671. The next prime is 20645683. The reversal of 20645673 is 37654602.

It is a cyclic number.

It is not a de Polignac number, because 20645673 - 2¹ = 20645671 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20645671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4936 + ... + 8102.

It is an arithmetic number, because the mean of its divisors is an integer number (1796256).

Almost surely, 2^20645673 is an apocalyptic number.

It is an amenable number.

20645673 is a deficient number, since it is larger than the sum of its proper divisors (8094423).

20645673 is a wasteful number, since it uses less digits than its factorization.

20645673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3264.

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 20645673 is about 4543.7509834937. The cubic root of 20645673 is about 274.3319232121.

The spelling of 20645673 in words is "twenty million, six hundred forty-five thousand, six hundred seventy-three".