20920845 has 32 divisors (see below), whose sum is σ = 36900864. Its totient is φ = 10036800.

The previous prime is 20920841. The next prime is 20920847. The reversal of 20920845 is 54802902.

It is not a de Polignac number, because 20920845 - 2² = 20920841 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16380 + ... + 17610.

It is an arithmetic number, because the mean of its divisors is an integer number (1153152).

Almost surely, 2^20920845 is an apocalyptic number.

It is an amenable number.

20920845 is a deficient number, since it is larger than the sum of its proper divisors (15980019).

20920845 is a wasteful number, since it uses less digits than its factorization.

20920845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1353.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20920845 is about 4573.9310226544. The cubic root of 20920845 is about 275.5453420803.

The spelling of 20920845 in words is "twenty million, nine hundred twenty thousand, eight hundred forty-five".