20307945 has 64 divisors (see below), whose sum is σ = 40697856. Its totient is φ = 8432640.

The previous prime is 20307929. The next prime is 20307953. The reversal of 20307945 is 54970302.

It is not a de Polignac number, because 20307945 - 2⁴ = 20307929 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 55152 + ... + 55518.

It is an arithmetic number, because the mean of its divisors is an integer number (635904).

Almost surely, 2^20307945 is an apocalyptic number.

It is an amenable number.

20307945 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

20307945 is a wasteful number, since it uses less digits than its factorization.

20307945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430.

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 20307945 is about 4506.4337341184. The cubic root of 20307945 is about 272.8278241859.

The spelling of 20307945 in words is "twenty million, three hundred seven thousand, nine hundred forty-five".