20952521 has 2 divisors, whose sum is σ = 20952522. Its totient is φ = 20952520.

The previous prime is 20952479. The next prime is 20952539. The reversal of 20952521 is 12525902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15840400 + 5112121 = 3980^2 + 2261^2 .

It is a cyclic number.

It is not a de Polignac number, because 20952521 - 2⁶ = 20952457 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20952541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10476260 + 10476261.

It is an arithmetic number, because the mean of its divisors is an integer number (10476261).

Almost surely, 2^20952521 is an apocalyptic number.

It is an amenable number.

20952521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20952521 is an equidigital number, since it uses as much as digits as its factorization.

20952521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 20952521 is about 4577.3923799473. The cubic root of 20952521 is about 275.6843385833.

The spelling of 20952521 in words is "twenty million, nine hundred fifty-two thousand, five hundred twenty-one".