20172771 has 12 divisors (see below), whose sum is σ = 30405648. Its totient is φ = 12863664.

The previous prime is 20172743. The next prime is 20172781. The reversal of 20172771 is 17727102.

It is not a de Polignac number, because 20172771 - 2⁶ = 20172707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20172731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48520 + ... + 48933.

It is an arithmetic number, because the mean of its divisors is an integer number (2533804).

Almost surely, 2^20172771 is an apocalyptic number.

20172771 is a deficient number, since it is larger than the sum of its proper divisors (10232877).

20172771 is a wasteful number, since it uses less digits than its factorization.

20172771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97482 (or 97479 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 27.

The square root of 20172771 is about 4491.4108028547. The cubic root of 20172771 is about 272.2211427850.

Adding to 20172771 its reverse (17727102), we get a palindrome (37899873).

The spelling of 20172771 in words is "twenty million, one hundred seventy-two thousand, seven hundred seventy-one".