20534981 has 2 divisors, whose sum is σ = 20534982. Its totient is φ = 20534980.

The previous prime is 20534977. The next prime is 20534999. The reversal of 20534981 is 18943502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17926756 + 2608225 = 4234^2 + 1615^2 .

It is a cyclic number.

It is not a de Polignac number, because 20534981 - 2² = 20534977 is a prime.

It is a super-2 number, since 2×20534981² = 843370889340722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20534971) 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, 10267490 + 10267491.

It is an arithmetic number, because the mean of its divisors is an integer number (10267491).

Almost surely, 2^20534981 is an apocalyptic number.

It is an amenable number.

20534981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20534981 is an equidigital number, since it uses as much as digits as its factorization.

20534981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20534981 is about 4531.5539277383. The cubic root of 20534981 is about 273.8407665209.

The spelling of 20534981 in words is "twenty million, five hundred thirty-four thousand, nine hundred eighty-one".