20770221 has 8 divisors (see below), whose sum is σ = 27719424. Its totient is φ = 13833920.

The previous prime is 20770187. The next prime is 20770229. The reversal of 20770221 is 12207702.

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 20770221 - 2⁹ = 20769709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20770229) 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, 1540 + ... + 6626.

It is an arithmetic number, because the mean of its divisors is an integer number (3464928).

Almost surely, 2^20770221 is an apocalyptic number.

It is an amenable number.

20770221 is a deficient number, since it is larger than the sum of its proper divisors (6949203).

20770221 is a wasteful number, since it uses less digits than its factorization.

20770221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6451.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 20770221 is about 4557.4357921972. The cubic root of 20770221 is about 274.8824665785.

Adding to 20770221 its reverse (12207702), we get a palindrome (32977923).

The spelling of 20770221 in words is "twenty million, seven hundred seventy thousand, two hundred twenty-one".