2099521 has 2 divisors, whose sum is σ = 2099522. Its totient is φ = 2099520.

The previous prime is 2099507. The next prime is 2099543. The reversal of 2099521 is 1259902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2073600 + 25921 = 1440^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 2099521 - 2⁷ = 2099393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2099521.

It is not a weakly prime, because it can be changed into another prime (2099021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1049760 + 1049761.

It is an arithmetic number, because the mean of its divisors is an integer number (1049761).

2^2099521 is an apocalyptic number.

It is an amenable number.

2099521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2099521 is an equidigital number, since it uses as much as digits as its factorization.

2099521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 2099521 is about 1448.9723944920. The cubic root of 2099521 is about 128.0481792914.

It can be divided in two parts, 209 and 9521, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 2099521 in words is "two million, ninety-nine thousand, five hundred twenty-one".