20757843 has 16 divisors (see below), whose sum is σ = 30979200. Its totient is φ = 13736520.

The previous prime is 20757809. The next prime is 20757853. The reversal of 20757843 is 34875702.

It is not a de Polignac number, because 20757843 - 2¹⁶ = 20692307 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20757798 and 20757807.

It is not an unprimeable number, because it can be changed into a prime (20757853) 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, 988 + ... + 6518.

It is an arithmetic number, because the mean of its divisors is an integer number (1936200).

Almost surely, 2^20757843 is an apocalyptic number.

20757843 is a deficient number, since it is larger than the sum of its proper divisors (10221357).

20757843 is a wasteful number, since it uses less digits than its factorization.

20757843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5679 (or 5673 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 20757843 is about 4556.0775893305. The cubic root of 20757843 is about 274.8278503838.

The spelling of 20757843 in words is "twenty million, seven hundred fifty-seven thousand, eight hundred forty-three".