20345761 has 2 divisors, whose sum is σ = 20345762. Its totient is φ = 20345760.

The previous prime is 20345749. The next prime is 20345771. The reversal of 20345761 is 16754302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12645136 + 7700625 = 3556^2 + 2775^2 .

It is a cyclic number.

It is not a de Polignac number, because 20345761 - 2⁹ = 20345249 is a prime.

It is not a weakly prime, because it can be changed into another prime (20345771) 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, 10172880 + 10172881.

It is an arithmetic number, because the mean of its divisors is an integer number (10172881).

Almost surely, 2^20345761 is an apocalyptic number.

It is an amenable number.

20345761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20345761 is an equidigital number, since it uses as much as digits as its factorization.

20345761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20345761 is about 4510.6275616592. The cubic root of 20345761 is about 272.9970659875.

The spelling of 20345761 in words is "twenty million, three hundred forty-five thousand, seven hundred sixty-one".