20442649 has 2 divisors, whose sum is σ = 20442650. Its totient is φ = 20442648.

The previous prime is 20442629. The next prime is 20442659. The reversal of 20442649 is 94624402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20313049 + 129600 = 4507^2 + 360^2 .

It is a cyclic number.

It is not a de Polignac number, because 20442649 - 2¹¹ = 20440601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20442649.

It is not a weakly prime, because it can be changed into another prime (20442629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10221324 + 10221325.

It is an arithmetic number, because the mean of its divisors is an integer number (10221325).

Almost surely, 2^20442649 is an apocalyptic number.

It is an amenable number.

20442649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20442649 is an equidigital number, since it uses as much as digits as its factorization.

20442649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 20442649 is about 4521.3547748435. The cubic root of 20442649 is about 273.4297239193.

The spelling of 20442649 in words is "twenty million, four hundred forty-two thousand, six hundred forty-nine".