20536993 has 2 divisors, whose sum is σ = 20536994. Its totient is φ = 20536992.

The previous prime is 20536951. The next prime is 20537009. The reversal of 20536993 is 39963502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20493729 + 43264 = 4527^2 + 208^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20536993 is a prime.

It is not a weakly prime, because it can be changed into another prime (20536913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10268496 + 10268497.

It is an arithmetic number, because the mean of its divisors is an integer number (10268497).

Almost surely, 2^20536993 is an apocalyptic number.

It is an amenable number.

20536993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20536993 is an equidigital number, since it uses as much as digits as its factorization.

20536993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 37.

The square root of 20536993 is about 4531.7759212035. The cubic root of 20536993 is about 273.8497097908.

It can be divided in two parts, 205 and 36993, that multiplied together give a triangular number (7583565 = T₃₈₉₄).

The spelling of 20536993 in words is "twenty million, five hundred thirty-six thousand, nine hundred ninety-three".