20673609 has 16 divisors (see below), whose sum is σ = 30293760. Its totient is φ = 12436560.

The previous prime is 20673599. The next prime is 20673613. The reversal of 20673609 is 90637602.

It is not a de Polignac number, because 20673609 - 2⁴ = 20673593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20673609.

It is not an unprimeable number, because it can be changed into a prime (20673629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2334 + ... + 6840.

It is an arithmetic number, because the mean of its divisors is an integer number (1893360).

Almost surely, 2^20673609 is an apocalyptic number.

It is an amenable number.

20673609 is a deficient number, since it is larger than the sum of its proper divisors (9620151).

20673609 is a wasteful number, since it uses less digits than its factorization.

20673609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4660.

The product of its (nonzero) digits is 13608, while the sum is 33.

The square root of 20673609 is about 4546.8240564156. The cubic root of 20673609 is about 274.4556017921.

The spelling of 20673609 in words is "twenty million, six hundred seventy-three thousand, six hundred nine".