20634645 has 16 divisors (see below), whose sum is σ = 33719040. Its totient is φ = 10770624.

The previous prime is 20634643. The next prime is 20634697. The reversal of 20634645 is 54643602.

It is not a de Polignac number, because 20634645 - 2¹ = 20634643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20634643) 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, 13930 + ... + 15339.

It is an arithmetic number, because the mean of its divisors is an integer number (2107440).

Almost surely, 2^20634645 is an apocalyptic number.

It is an amenable number.

20634645 is a deficient number, since it is larger than the sum of its proper divisors (13084395).

20634645 is a wasteful number, since it uses less digits than its factorization.

20634645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29324.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 20634645 is about 4542.5372865833. The cubic root of 20634645 is about 274.2830692097.

The spelling of 20634645 in words is "twenty million, six hundred thirty-four thousand, six hundred forty-five".