1521132421205 has 4 divisors (see below), whose sum is σ = 1825358905452. Its totient is φ = 1216905936960.

The previous prime is 1521132421199. The next prime is 1521132421243. The reversal of 1521132421205 is 5021242311251.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1192553545681 + 328578875524 = 1092041^2 + 573218^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1521132421205 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 152113242116 + ... + 152113242125.

It is an arithmetic number, because the mean of its divisors is an integer number (456339726363).

Almost surely, 2^{1521132421205} is an apocalyptic number.

It is an amenable number.

1521132421205 is a deficient number, since it is larger than the sum of its proper divisors (304226484247).

1521132421205 is an equidigital number, since it uses as much as digits as its factorization.

1521132421205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304226484246.

The product of its (nonzero) digits is 4800, while the sum is 29.

Adding to 1521132421205 its reverse (5021242311251), we get a palindrome (6542374732456).

The spelling of 1521132421205 in words is "one trillion, five hundred twenty-one billion, one hundred thirty-two million, four hundred twenty-one thousand, two hundred five".