20964187 has 4 divisors (see below), whose sum is σ = 21687120. Its totient is φ = 20241256.

The previous prime is 20964169. The next prime is 20964197. The reversal of 20964187 is 78146902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20964187 - 2⁷ = 20964059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20964107) 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 3 ways as a sum of consecutive naturals, for example, 361423 + ... + 361480.

It is an arithmetic number, because the mean of its divisors is an integer number (5421780).

Almost surely, 2^20964187 is an apocalyptic number.

20964187 is a deficient number, since it is larger than the sum of its proper divisors (722933).

20964187 is an equidigital number, since it uses as much as digits as its factorization.

20964187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722932.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20964187 is about 4578.6665089303. Note that the first 3 decimals coincide. The cubic root of 20964187 is about 275.7354945084.

The spelling of 20964187 in words is "twenty million, nine hundred sixty-four thousand, one hundred eighty-seven".