20007745 has 4 divisors (see below), whose sum is σ = 24009300. Its totient is φ = 16006192.

The previous prime is 20007737. The next prime is 20007749. The reversal of 20007745 is 54770002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7219969 + 12787776 = 2687^2 + 3576^2 .

It is a cyclic number.

It is not a de Polignac number, because 20007745 - 2³ = 20007737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20007749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000770 + ... + 2000779.

It is an arithmetic number, because the mean of its divisors is an integer number (6002325).

Almost surely, 2^20007745 is an apocalyptic number.

It is an amenable number.

20007745 is a deficient number, since it is larger than the sum of its proper divisors (4001555).

20007745 is an equidigital number, since it uses as much as digits as its factorization.

20007745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4001554.

The product of its (nonzero) digits is 1960, while the sum is 25.

The square root of 20007745 is about 4473.0017885085. The cubic root of 20007745 is about 271.4767957450.

Adding to 20007745 its reverse (54770002), we get a palindrome (74777747).

The spelling of 20007745 in words is "twenty million, seven thousand, seven hundred forty-five".