20351081 has 2 divisors, whose sum is σ = 20351082. Its totient is φ = 20351080.

The previous prime is 20351077. The next prime is 20351087. The reversal of 20351081 is 18015302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18619225 + 1731856 = 4315^2 + 1316^2 .

It is a cyclic number.

It is not a de Polignac number, because 20351081 - 2² = 20351077 is a prime.

It is a super-2 number, since 2×20351081² = 828332995737122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20351087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10175540 + 10175541.

It is an arithmetic number, because the mean of its divisors is an integer number (10175541).

Almost surely, 2^20351081 is an apocalyptic number.

It is an amenable number.

20351081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20351081 is an equidigital number, since it uses as much as digits as its factorization.

20351081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 20351081 is about 4511.2172414992. The cubic root of 20351081 is about 273.0208582953.

Adding to 20351081 its reverse (18015302), we get a palindrome (38366383).

The spelling of 20351081 in words is "twenty million, three hundred fifty-one thousand, eighty-one".