20645672 has 16 divisors (see below), whose sum is σ = 38760000. Its totient is φ = 10309680.

The previous prime is 20645671. The next prime is 20645683. The reversal of 20645672 is 27654602.

It is not an unprimeable number, because it can be changed into a prime (20645671) 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 3 ways as a sum of consecutive naturals, for example, 9329 + ... + 11327.

It is an arithmetic number, because the mean of its divisors is an integer number (2422500).

Almost surely, 2^20645672 is an apocalyptic number.

It is an amenable number.

20645672 is a deficient number, since it is larger than the sum of its proper divisors (18114328).

20645672 is a wasteful number, since it uses less digits than its factorization.

20645672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296 (or 3292 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 20645672 is about 4543.7508734525. The cubic root of 20645672 is about 274.3319187829.

The spelling of 20645672 in words is "twenty million, six hundred forty-five thousand, six hundred seventy-two".