20757231 has 12 divisors (see below), whose sum is σ = 32708520. Its totient is φ = 12580080.

The previous prime is 20757229. The next prime is 20757257. The reversal of 20757231 is 13275702.

It is not a de Polignac number, because 20757231 - 2¹ = 20757229 is a prime.

It is a super-2 number, since 2×20757231² = 861725277574722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20757195 and 20757204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20757031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104736 + ... + 104933.

It is an arithmetic number, because the mean of its divisors is an integer number (2725710).

Almost surely, 2^20757231 is an apocalyptic number.

20757231 is a deficient number, since it is larger than the sum of its proper divisors (11951289).

20757231 is a wasteful number, since it uses less digits than its factorization.

20757231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209686 (or 209683 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 20757231 is about 4556.0104258002. The cubic root of 20757231 is about 274.8251494561.

The spelling of 20757231 in words is "twenty million, seven hundred fifty-seven thousand, two hundred thirty-one".