21398026571 has 8 divisors (see below), whose sum is σ = 21610293264. Its totient is φ = 21186161920.

The previous prime is 21398026541. The next prime is 21398026579. The reversal of 21398026571 is 17562089312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21398026571 is a prime.

It is a super-2 number, since 2×21398026571² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21398026579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7031 + ... + 206991.

It is an arithmetic number, because the mean of its divisors is an integer number (2701286658).

Almost surely, 2^21398026571 is an apocalyptic number.

21398026571 is a deficient number, since it is larger than the sum of its proper divisors (212266693).

21398026571 is a wasteful number, since it uses less digits than its factorization.

21398026571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201021.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 21398026571 in words is "twenty-one billion, three hundred ninety-eight million, twenty-six thousand, five hundred seventy-one".