20971529 has 2 divisors, whose sum is σ = 20971530. Its totient is φ = 20971528.

The previous prime is 20971507. The next prime is 20971537. The reversal of 20971529 is 92517902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19404025 + 1567504 = 4405^2 + 1252^2 .

It is a cyclic number.

It is not a de Polignac number, because 20971529 - 2¹² = 20967433 is a prime.

It is not a weakly prime, because it can be changed into another prime (20977529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10485764 + 10485765.

It is an arithmetic number, because the mean of its divisors is an integer number (10485765).

Almost surely, 2^20971529 is an apocalyptic number.

It is an amenable number.

20971529 is a deficient number, since it is larger than the sum of its proper divisors (1).

20971529 is an equidigital number, since it uses as much as digits as its factorization.

20971529 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 20971529 is about 4579.4682005665. The cubic root of 20971529 is about 275.7676797730.

The spelling of 20971529 in words is "twenty million, nine hundred seventy-one thousand, five hundred twenty-nine".