20707421 has 16 divisors (see below), whose sum is σ = 24796800. Its totient is φ = 16916928.

The previous prime is 20707403. The next prime is 20707433. The reversal of 20707421 is 12470702.

It is not a de Polignac number, because 20707421 - 2²² = 16513117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20707441) 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, 16235 + ... + 17463.

It is an arithmetic number, because the mean of its divisors is an integer number (1549800).

Almost surely, 2^20707421 is an apocalyptic number.

It is an amenable number.

20707421 is a deficient number, since it is larger than the sum of its proper divisors (4089379).

20707421 is a wasteful number, since it uses less digits than its factorization.

20707421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 20707421 is about 4550.5407370993. The cubic root of 20707421 is about 274.6051457229.

The spelling of 20707421 in words is "twenty million, seven hundred seven thousand, four hundred twenty-one".