20197771 has 16 divisors (see below), whose sum is σ = 23141376. Its totient is φ = 17460000.

The previous prime is 20197769. The next prime is 20197783. The reversal of 20197771 is 17779102.

It is a cyclic number.

It is not a de Polignac number, because 20197771 - 2¹ = 20197769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20197721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20316 + ... + 21286.

It is an arithmetic number, because the mean of its divisors is an integer number (1446336).

Almost surely, 2^20197771 is an apocalyptic number.

20197771 is a deficient number, since it is larger than the sum of its proper divisors (2943605).

20197771 is a wasteful number, since it uses less digits than its factorization.

20197771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074.

The product of its (nonzero) digits is 6174, while the sum is 34.

The square root of 20197771 is about 4494.1930310124. The cubic root of 20197771 is about 272.3335503987. Note that the first 3 decimals are identical.

It can be divided in two parts, 20 and 197771, that added together give a palindrome (197791).

The spelling of 20197771 in words is "twenty million, one hundred ninety-seven thousand, seven hundred seventy-one".