21612043135157 has 4 divisors (see below), whose sum is σ = 21626917219980. Its totient is φ = 21597169050336.

The previous prime is 21612043135147. The next prime is 21612043135169. The reversal of 21612043135157 is 75153134021612.

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 20111224578916 + 1500818556241 = 4484554^2 + 1225079^2 .

It is a cyclic number.

It is not a de Polignac number, because 21612043135157 - 2¹⁴ = 21612043118773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612043135147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7437040232 + ... + 7437043137.

It is an arithmetic number, because the mean of its divisors is an integer number (5406729304995).

Almost surely, 2^{21612043135157} is an apocalyptic number.

It is an amenable number.

21612043135157 is a deficient number, since it is larger than the sum of its proper divisors (14874084823).

21612043135157 is a wasteful number, since it uses less digits than its factorization.

21612043135157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14874084822.

The product of its (nonzero) digits is 151200, while the sum is 41.

Adding to 21612043135157 its reverse (75153134021612), we get a palindrome (96765177156769).

The spelling of 21612043135157 in words is "twenty-one trillion, six hundred twelve billion, forty-three million, one hundred thirty-five thousand, one hundred fifty-seven".