20667975 has 12 divisors (see below), whose sum is σ = 34171176. Its totient is φ = 11022880.

The previous prime is 20667973. The next prime is 20668027. The reversal of 20667975 is 57976602.

It is a happy number.

It is not a de Polignac number, because 20667975 - 2¹ = 20667973 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20667973) 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, 137712 + ... + 137861.

It is an arithmetic number, because the mean of its divisors is an integer number (2847598).

Almost surely, 2^20667975 is an apocalyptic number.

20667975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20667975 is a deficient number, since it is larger than the sum of its proper divisors (13503201).

20667975 is a wasteful number, since it uses less digits than its factorization.

20667975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275586 (or 275581 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 42.

The square root of 20667975 is about 4546.2044608662. The cubic root of 20667975 is about 274.4306678558.

The spelling of 20667975 in words is "twenty million, six hundred sixty-seven thousand, nine hundred seventy-five".