20995667 has 12 divisors (see below), whose sum is σ = 26644536. Its totient is φ = 16359840.

The previous prime is 20995657. The next prime is 20995693. The reversal of 20995667 is 76659902.

It is not a de Polignac number, because 20995667 - 2⁸ = 20995411 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20995657) 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 11 ways as a sum of consecutive naturals, for example, 18938 + ... + 20015.

It is an arithmetic number, because the mean of its divisors is an integer number (2220378).

Almost surely, 2^20995667 is an apocalyptic number.

20995667 is a deficient number, since it is larger than the sum of its proper divisors (5648869).

20995667 is a wasteful number, since it uses less digits than its factorization.

20995667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38978 (or 38971 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 20995667 is about 4582.1029015071. The cubic root of 20995667 is about 275.8734410655.

The spelling of 20995667 in words is "twenty million, nine hundred ninety-five thousand, six hundred sixty-seven".