20907445 has 16 divisors (see below), whose sum is σ = 27466992. Its totient is φ = 15183360.

The previous prime is 20907421. The next prime is 20907449. The reversal of 20907445 is 54470902.

It can be written as a sum of positive squares in 8 ways, for example, as 6115729 + 14791716 = 2473^2 + 3846^2 .

It is not a de Polignac number, because 20907445 - 2⁷ = 20907317 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 (20907449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1329 + ... + 6601.

It is an arithmetic number, because the mean of its divisors is an integer number (1716687).

Almost surely, 2^20907445 is an apocalyptic number.

It is an amenable number.

20907445 is a deficient number, since it is larger than the sum of its proper divisors (6559547).

20907445 is a wasteful number, since it uses less digits than its factorization.

20907445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5352.

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

The square root of 20907445 is about 4572.4659648815. The cubic root of 20907445 is about 275.4864997123.

The spelling of 20907445 in words is "twenty million, nine hundred seven thousand, four hundred forty-five".