20820771 has 6 divisors (see below), whose sum is σ = 30074460. Its totient is φ = 13880508.

The previous prime is 20820769. The next prime is 20820781. The reversal of 20820771 is 17702802.

It is not a de Polignac number, because 20820771 - 2¹ = 20820769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20820721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1156701 + ... + 1156718.

It is an arithmetic number, because the mean of its divisors is an integer number (5012410).

Almost surely, 2^20820771 is an apocalyptic number.

20820771 is a deficient number, since it is larger than the sum of its proper divisors (9253689).

20820771 is a wasteful number, since it uses less digits than its factorization.

20820771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2313425 (or 2313422 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 20820771 is about 4562.9783036960. The cubic root of 20820771 is about 275.1052864067.

The spelling of 20820771 in words is "twenty million, eight hundred twenty thousand, seven hundred seventy-one".