20290649 has 2 divisors, whose sum is σ = 20290650. Its totient is φ = 20290648.

The previous prime is 20290609. The next prime is 20290657. The reversal of 20290649 is 94609202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19642624 + 648025 = 4432^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 20290649 - 2²⁰ = 19242073 is a prime.

It is not a weakly prime, because it can be changed into another prime (20290609) 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, 10145324 + 10145325.

It is an arithmetic number, because the mean of its divisors is an integer number (10145325).

Almost surely, 2^20290649 is an apocalyptic number.

It is an amenable number.

20290649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20290649 is an equidigital number, since it uses as much as digits as its factorization.

20290649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20290649 is about 4504.5142912416. The cubic root of 20290649 is about 272.7503476066.

The spelling of 20290649 in words is "twenty million, two hundred ninety thousand, six hundred forty-nine".