20490761 has 2 divisors, whose sum is σ = 20490762. Its totient is φ = 20490760.

The previous prime is 20490749. The next prime is 20490787. The reversal of 20490761 is 16709402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19758025 + 732736 = 4445^2 + 856^2 .

It is a cyclic number.

It is not a de Polignac number, because 20490761 - 2¹⁰ = 20489737 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20490161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10245380 + 10245381.

It is an arithmetic number, because the mean of its divisors is an integer number (10245381).

Almost surely, 2^20490761 is an apocalyptic number.

It is an amenable number.

20490761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20490761 is an equidigital number, since it uses as much as digits as its factorization.

20490761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 20490761 is about 4526.6721772180. The cubic root of 20490761 is about 273.6440624819.

The spelling of 20490761 in words is "twenty million, four hundred ninety thousand, seven hundred sixty-one".