20913843 has 32 divisors (see below), whose sum is σ = 30369600. Its totient is φ = 12773376.

The previous prime is 20913839. The next prime is 20913857. The reversal of 20913843 is 34831902.

It is not a de Polignac number, because 20913843 - 2² = 20913839 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20913843.

It is not an unprimeable number, because it can be changed into a prime (20913803) 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, 234943 + ... + 235031.

It is an arithmetic number, because the mean of its divisors is an integer number (949050).

Almost surely, 2^20913843 is an apocalyptic number.

20913843 is a deficient number, since it is larger than the sum of its proper divisors (9455757).

20913843 is a wasteful number, since it uses less digits than its factorization.

20913843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20913843 is about 4573.1655338507. The cubic root of 20913843 is about 275.5145978828.

The spelling of 20913843 in words is "twenty million, nine hundred thirteen thousand, eight hundred forty-three".