20640195 has 24 divisors (see below), whose sum is σ = 35885616. Its totient is φ = 10974528.

The previous prime is 20640181. The next prime is 20640233. The reversal of 20640195 is 59104602.

20640195 is a `hidden beast` number, since 2 + 0 + 640 + 19 + 5 = 666.

It is not a de Polignac number, because 20640195 - 2⁵ = 20640163 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23097 + ... + 23973.

It is an arithmetic number, because the mean of its divisors is an integer number (1495234).

Almost surely, 2^20640195 is an apocalyptic number.

20640195 is a deficient number, since it is larger than the sum of its proper divisors (15245421).

20640195 is a wasteful number, since it uses less digits than its factorization.

20640195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411 (or 1408 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20640195 is about 4543.1481375804. The cubic root of 20640195 is about 274.3076578659.

Adding to 20640195 its reverse (59104602), we get a palindrome (79744797).

It can be divided in two parts, 206 and 40195, that added together give a square (40401 = 201²).

The spelling of 20640195 in words is "twenty million, six hundred forty thousand, one hundred ninety-five".