20531643237 has 24 divisors (see below), whose sum is σ = 35148824256. Its totient is φ = 11732366592.

The previous prime is 20531643229. The next prime is 20531643239. The reversal of 20531643237 is 73234613502.

20531643237 is a `hidden beast` number, since 2 + 0 + 5 + 3 + 1 + 643 + 2 + 3 + 7 = 666.

It is not a de Polignac number, because 20531643237 - 2³ = 20531643229 is a prime.

It is a super-2 number, since 2×20531643237² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20531643239) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6033468 + ... + 6036869.

It is an arithmetic number, because the mean of its divisors is an integer number (1464534344).

Almost surely, 2^20531643237 is an apocalyptic number.

20531643237 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20531643237 is a deficient number, since it is larger than the sum of its proper divisors (14617181019).

20531643237 is an equidigital number, since it uses as much as digits as its factorization.

20531643237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12070359 (or 12070347 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 36.

The spelling of 20531643237 in words is "twenty billion, five hundred thirty-one million, six hundred forty-three thousand, two hundred thirty-seven".