21152520114437 has 4 divisors (see below), whose sum is σ = 21154076490336. Its totient is φ = 21150963738540.

The previous prime is 21152520114419. The next prime is 21152520114503. The reversal of 21152520114437 is 73441102525112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21152520114437 - 2⁶ = 21152520114373 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21152520114437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152520414437) 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, 778167563 + ... + 778194744.

It is an arithmetic number, because the mean of its divisors is an integer number (5288519122584).

Almost surely, 2^{21152520114437} is an apocalyptic number.

It is an amenable number.

21152520114437 is a deficient number, since it is larger than the sum of its proper divisors (1556375899).

21152520114437 is a wasteful number, since it uses less digits than its factorization.

21152520114437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1556375898.

The product of its (nonzero) digits is 67200, while the sum is 38.

Adding to 21152520114437 its reverse (73441102525112), we get a palindrome (94593622639549).

The spelling of 21152520114437 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred twenty million, one hundred fourteen thousand, four hundred thirty-seven".