20771021 has 8 divisors (see below), whose sum is σ = 21315360. Its totient is φ = 20229552.

The previous prime is 20770973. The next prime is 20771029. The reversal of 20771021 is 12017702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20771021 - 2¹⁸ = 20508877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20770984 and 20771002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20771029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27971 + ... + 28703.

It is an arithmetic number, because the mean of its divisors is an integer number (2664420).

Almost surely, 2^20771021 is an apocalyptic number.

It is an amenable number.

20771021 is a deficient number, since it is larger than the sum of its proper divisors (544339).

20771021 is an equidigital number, since it uses as much as digits as its factorization.

20771021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1435.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 20771021 is about 4557.5235600049. The cubic root of 20771021 is about 274.8859957200.

Adding to 20771021 its reverse (12017702), we get a palindrome (32788723).

The spelling of 20771021 in words is "twenty million, seven hundred seventy-one thousand, twenty-one".