20529491 has 4 divisors (see below), whose sum is σ = 20554800. Its totient is φ = 20504184.

The previous prime is 20529473. The next prime is 20529499. The reversal of 20529491 is 19492502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20529491 - 2⁶ = 20529427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20529499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11396 + ... + 13073.

It is an arithmetic number, because the mean of its divisors is an integer number (5138700).

Almost surely, 2^20529491 is an apocalyptic number.

20529491 is a deficient number, since it is larger than the sum of its proper divisors (25309).

20529491 is an equidigital number, since it uses as much as digits as its factorization.

20529491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25308.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 20529491 is about 4530.9481347727. The cubic root of 20529491 is about 273.8163606903.

The spelling of 20529491 in words is "twenty million, five hundred twenty-nine thousand, four hundred ninety-one".