20780571 has 32 divisors (see below), whose sum is σ = 33067008. Its totient is φ = 11358720.

The previous prime is 20780549. The next prime is 20780581. The reversal of 20780571 is 17508702.

It is a happy number.

It is not a de Polignac number, because 20780571 - 2⁹ = 20780059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20780531) 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 31 ways as a sum of consecutive naturals, for example, 89071 + ... + 89303.

It is an arithmetic number, because the mean of its divisors is an integer number (1033344).

Almost surely, 2^20780571 is an apocalyptic number.

20780571 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20780571 is a deficient number, since it is larger than the sum of its proper divisors (12286437).

20780571 is a wasteful number, since it uses less digits than its factorization.

20780571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411.

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 20780571 is about 4558.5711577204. The cubic root of 20780571 is about 274.9281178515.

The spelling of 20780571 in words is "twenty million, seven hundred eighty thousand, five hundred seventy-one".