20106649 has 2 divisors, whose sum is σ = 20106650. Its totient is φ = 20106648.

The previous prime is 20106643. The next prime is 20106659. The reversal of 20106649 is 94660102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18966025 + 1140624 = 4355^2 + 1068^2 .

It is a cyclic number.

It is not a de Polignac number, because 20106649 - 2³ = 20106641 is a prime.

It is not a weakly prime, because it can be changed into another prime (20106641) 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, 10053324 + 10053325.

It is an arithmetic number, because the mean of its divisors is an integer number (10053325).

Almost surely, 2^20106649 is an apocalyptic number.

It is an amenable number.

20106649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20106649 is an equidigital number, since it uses as much as digits as its factorization.

20106649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20106649 is about 4484.0438222658. The cubic root of 20106649 is about 271.9233897926.

The spelling of 20106649 in words is "twenty million, one hundred six thousand, six hundred forty-nine".