20528551 has 2 divisors, whose sum is σ = 20528552. Its totient is φ = 20528550.

The previous prime is 20528539. The next prime is 20528567. The reversal of 20528551 is 15582502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20528551 - 2⁷ = 20528423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20528591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264275 + 10264276.

It is an arithmetic number, because the mean of its divisors is an integer number (10264276).

Almost surely, 2^20528551 is an apocalyptic number.

20528551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528551 is an equidigital number, since it uses as much as digits as its factorization.

20528551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 20528551 is about 4530.8444025369. The cubic root of 20528551 is about 273.8121814780.

The spelling of 20528551 in words is "twenty million, five hundred twenty-eight thousand, five hundred fifty-one".