20937643 has 2 divisors, whose sum is σ = 20937644. Its totient is φ = 20937642.

The previous prime is 20937619. The next prime is 20937649. The reversal of 20937643 is 34673902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20937643 - 2⁹ = 20937131 is a prime.

It is a super-3 number, since 3×20937643³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20937599 and 20937608.

It is not a weakly prime, because it can be changed into another prime (20937649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10468821 + 10468822.

It is an arithmetic number, because the mean of its divisors is an integer number (10468822).

Almost surely, 2^20937643 is an apocalyptic number.

20937643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20937643 is an equidigital number, since it uses as much as digits as its factorization.

20937643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 34.

The square root of 20937643 is about 4575.7669302533. The cubic root of 20937643 is about 275.6190703386.

The spelling of 20937643 in words is "twenty million, nine hundred thirty-seven thousand, six hundred forty-three".