21896571967513 has 4 divisors (see below), whose sum is σ = 21896590095540. Its totient is φ = 21896553839488.

The previous prime is 21896571967511. The next prime is 21896571967549. The reversal of 21896571967513 is 31576917569812.

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 6057151032384 + 15839420935129 = 2461128^2 + 3979877^2 .

It is a cyclic number.

It is not a de Polignac number, because 21896571967513 - 2¹ = 21896571967511 is a prime.

It is a super-2 number, since 2×21896571967513² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21896571967511) 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, 7112068 + ... + 9714661.

It is an arithmetic number, because the mean of its divisors is an integer number (5474147523885).

Almost surely, 2^{21896571967513} is an apocalyptic number.

It is an amenable number.

21896571967513 is a deficient number, since it is larger than the sum of its proper divisors (18128027).

21896571967513 is a wasteful number, since it uses less digits than its factorization.

21896571967513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18128026.

The product of its digits is 171460800, while the sum is 70.

The spelling of 21896571967513 in words is "twenty-one trillion, eight hundred ninety-six billion, five hundred seventy-one million, nine hundred sixty-seven thousand, five hundred thirteen".