20009761 has 2 divisors, whose sum is σ = 20009762. Its totient is φ = 20009760.

The previous prime is 20009753. The next prime is 20009813. The reversal of 20009761 is 16790002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19088161 + 921600 = 4369^2 + 960^2 .

It is a cyclic number.

It is not a de Polignac number, because 20009761 - 2³ = 20009753 is a prime.

It is not a weakly prime, because it can be changed into another prime (20009741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004880 + 10004881.

It is an arithmetic number, because the mean of its divisors is an integer number (10004881).

Almost surely, 2^20009761 is an apocalyptic number.

It is an amenable number.

20009761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20009761 is an equidigital number, since it uses as much as digits as its factorization.

20009761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 20009761 is about 4473.2271348547. The cubic root of 20009761 is about 271.4859135281.

Adding to 20009761 its reverse (16790002), we get a palindrome (36799763).

The spelling of 20009761 in words is "twenty million, nine thousand, seven hundred sixty-one".