20782061 has 2 divisors, whose sum is σ = 20782062. Its totient is φ = 20782060.

The previous prime is 20782051. The next prime is 20782081. The reversal of 20782061 is 16028702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16240900 + 4541161 = 4030^2 + 2131^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20782061 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20782061.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20782031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10391030 + 10391031.

It is an arithmetic number, because the mean of its divisors is an integer number (10391031).

Almost surely, 2^20782061 is an apocalyptic number.

It is an amenable number.

20782061 is a deficient number, since it is larger than the sum of its proper divisors (1).

20782061 is an equidigital number, since it uses as much as digits as its factorization.

20782061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20782061 is about 4558.7345831930. The cubic root of 20782061 is about 274.9346886223.

The spelling of 20782061 in words is "twenty million, seven hundred eighty-two thousand, sixty-one".