20490771 has 12 divisors (see below), whose sum is σ = 31781832. Its totient is φ = 11708928.

The previous prime is 20490761. The next prime is 20490787. The reversal of 20490771 is 17709402.

It is not a de Polignac number, because 20490771 - 2⁶ = 20490707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20490761) 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 11 ways as a sum of consecutive naturals, for example, 69550 + ... + 69843.

It is an arithmetic number, because the mean of its divisors is an integer number (2648486).

Almost surely, 2^20490771 is an apocalyptic number.

20490771 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20490771 is a deficient number, since it is larger than the sum of its proper divisors (11291061).

20490771 is a wasteful number, since it uses less digits than its factorization.

20490771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139410 (or 139403 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 20490771 is about 4526.6732817821. The cubic root of 20490771 is about 273.6441069969.

The spelling of 20490771 in words is "twenty million, four hundred ninety thousand, seven hundred seventy-one".