21396528287 has 8 divisors (see below), whose sum is σ = 22828090032. Its totient is φ = 19984182400.

The previous prime is 21396528221. The next prime is 21396528319. The reversal of 21396528287 is 78282569312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21396528287 - 2²⁸ = 21128092831 is a prime.

It is a super-2 number, since 2×21396528287² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21396528487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4801664 + ... + 4806117.

It is an arithmetic number, because the mean of its divisors is an integer number (2853511254).

Almost surely, 2^21396528287 is an apocalyptic number.

21396528287 is a deficient number, since it is larger than the sum of its proper divisors (1431561745).

21396528287 is a wasteful number, since it uses less digits than its factorization.

21396528287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9607929.

The product of its digits is 2903040, while the sum is 53.

The spelling of 21396528287 in words is "twenty-one billion, three hundred ninety-six million, five hundred twenty-eight thousand, two hundred eighty-seven".