27122121405 has 40 divisors (see below), whose sum is σ = 48792139704. Its totient is φ = 14413593600.

The previous prime is 27122121361. The next prime is 27122121421. The reversal of 27122121405 is 50412122172.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9180322596 + 17941798809 = 95814^2 + 133947^2 .

It is not a de Polignac number, because 27122121405 - 2⁷ = 27122121277 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5356 + ... + 232965.

Almost surely, 2^27122121405 is an apocalyptic number.

It is an amenable number.

27122121405 is a deficient number, since it is larger than the sum of its proper divisors (21670018299).

27122121405 is a wasteful number, since it uses less digits than its factorization.

27122121405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238619 (or 238610 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

Adding to 27122121405 its reverse (50412122172), we get a palindrome (77534243577).

The spelling of 27122121405 in words is "twenty-seven billion, one hundred twenty-two million, one hundred twenty-one thousand, four hundred five".