20667771 has 16 divisors (see below), whose sum is σ = 30844800. Its totient is φ = 13676904.

The previous prime is 20667737. The next prime is 20667811. The reversal of 20667771 is 17776602.

It is not a de Polignac number, because 20667771 - 2⁶ = 20667707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20668771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1000 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (1927800).

Almost surely, 2^20667771 is an apocalyptic number.

20667771 is a deficient number, since it is larger than the sum of its proper divisors (10177029).

20667771 is a wasteful number, since it uses less digits than its factorization.

20667771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5655 (or 5649 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 20667771 is about 4546.1820245124. The cubic root of 20667771 is about 274.4297649446.

The spelling of 20667771 in words is "twenty million, six hundred sixty-seven thousand, seven hundred seventy-one".