20520291 has 16 divisors (see below), whose sum is σ = 30296448. Its totient is φ = 12249600.

The previous prime is 20520289. The next prime is 20520299. The reversal of 20520291 is 19202502.

It is not a de Polignac number, because 20520291 - 2¹ = 20520289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20520299) 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 in 15 ways as a sum of consecutive naturals, for example, 2430 + ... + 6851.

It is an arithmetic number, because the mean of its divisors is an integer number (1893528).

Almost surely, 2^20520291 is an apocalyptic number.

20520291 is a deficient number, since it is larger than the sum of its proper divisors (9776157).

20520291 is a wasteful number, since it uses less digits than its factorization.

20520291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9362.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20520291 is about 4529.9327809582. The cubic root of 20520291 is about 273.7754522737.

Adding to 20520291 its reverse (19202502), we get a palindrome (39722793).

The spelling of 20520291 in words is "twenty million, five hundred twenty thousand, two hundred ninety-one".