2195638638 has 32 divisors (see below), whose sum is σ = 4673720736. Its totient is φ = 685252608.

The previous prime is 2195638589. The next prime is 2195638639. The reversal of 2195638638 is 8368365912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2195638639) 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, 36081 + ... + 75452.

It is an arithmetic number, because the mean of its divisors is an integer number (146053773).

Almost surely, 2^2195638638 is an apocalyptic number.

2195638638 is an abundant number, since it is smaller than the sum of its proper divisors (2478082098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2195638638 is a wasteful number, since it uses less digits than its factorization.

2195638638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111748.

The product of its digits is 1866240, while the sum is 51.

The square root of 2195638638 is about 46857.6422582272. The cubic root of 2195638638 is about 1299.7314313049.

The spelling of 2195638638 in words is "two billion, one hundred ninety-five million, six hundred thirty-eight thousand, six hundred thirty-eight".