20478061 has 2 divisors, whose sum is σ = 20478062. Its totient is φ = 20478060.

The previous prime is 20478043. The next prime is 20478071. The reversal of 20478061 is 16087402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15256836 + 5221225 = 3906^2 + 2285^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20478061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20478071) 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, 10239030 + 10239031.

It is an arithmetic number, because the mean of its divisors is an integer number (10239031).

Almost surely, 2^20478061 is an apocalyptic number.

It is an amenable number.

20478061 is a deficient number, since it is larger than the sum of its proper divisors (1).

20478061 is an equidigital number, since it uses as much as digits as its factorization.

20478061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 20478061 is about 4525.2691632653. The cubic root of 20478061 is about 273.5875167078.

The spelling of 20478061 in words is "twenty million, four hundred seventy-eight thousand, sixty-one".