20737643 has 2 divisors, whose sum is σ = 20737644. Its totient is φ = 20737642.

The previous prime is 20737631. The next prime is 20737663. The reversal of 20737643 is 34673702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20737643 - 2⁴ = 20737627 is a prime.

It is not a weakly prime, because it can be changed into another prime (20737663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10368821 + 10368822.

It is an arithmetic number, because the mean of its divisors is an integer number (10368822).

Almost surely, 2^20737643 is an apocalyptic number.

20737643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20737643 is an equidigital number, since it uses as much as digits as its factorization.

20737643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 32.

The square root of 20737643 is about 4553.8602306175. The cubic root of 20737643 is about 274.7386740609.

The spelling of 20737643 in words is "twenty million, seven hundred thirty-seven thousand, six hundred forty-three".