20924521 has 2 divisors, whose sum is σ = 20924522. Its totient is φ = 20924520.

The previous prime is 20924513. The next prime is 20924537. The reversal of 20924521 is 12542902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16362025 + 4562496 = 4045^2 + 2136^2 .

It is a cyclic number.

It is not a de Polignac number, because 20924521 - 2³ = 20924513 is a prime.

It is not a weakly prime, because it can be changed into another prime (20924551) 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, 10462260 + 10462261.

It is an arithmetic number, because the mean of its divisors is an integer number (10462261).

Almost surely, 2^20924521 is an apocalyptic number.

It is an amenable number.

20924521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20924521 is an equidigital number, since it uses as much as digits as its factorization.

20924521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20924521 is about 4574.3328475309. The cubic root of 20924521 is about 275.5614798185.

The spelling of 20924521 in words is "twenty million, nine hundred twenty-four thousand, five hundred twenty-one".