20523649 has 2 divisors, whose sum is σ = 20523650. Its totient is φ = 20523648.

The previous prime is 20523623. The next prime is 20523653. The reversal of 20523649 is 94632502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15944049 + 4579600 = 3993^2 + 2140^2 .

It is a cyclic number.

It is not a de Polignac number, because 20523649 - 2¹⁷ = 20392577 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20523649.

It is not a weakly prime, because it can be changed into another prime (20523149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10261824 + 10261825.

It is an arithmetic number, because the mean of its divisors is an integer number (10261825).

Almost surely, 2^20523649 is an apocalyptic number.

It is an amenable number.

20523649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20523649 is an equidigital number, since it uses as much as digits as its factorization.

20523649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 20523649 is about 4530.3034114726. The cubic root of 20523649 is about 273.7903852625.

The spelling of 20523649 in words is "twenty million, five hundred twenty-three thousand, six hundred forty-nine".