20945407 has 4 divisors (see below), whose sum is σ = 23937616. Its totient is φ = 17953200.

The previous prime is 20945399. The next prime is 20945461. The reversal of 20945407 is 70454902.

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

It is a cyclic number.

It is not a de Polignac number, because 20945407 - 2³ = 20945399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20945707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1496094 + ... + 1496107.

It is an arithmetic number, because the mean of its divisors is an integer number (5984404).

Almost surely, 2^20945407 is an apocalyptic number.

20945407 is a deficient number, since it is larger than the sum of its proper divisors (2992209).

20945407 is an equidigital number, since it uses as much as digits as its factorization.

20945407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992208.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20945407 is about 4576.6152339912. The cubic root of 20945407 is about 275.6531340584.

The spelling of 20945407 in words is "twenty million, nine hundred forty-five thousand, four hundred seven".