21115430571 has 8 divisors (see below), whose sum is σ = 28154880144. Its totient is φ = 14076467360.

The previous prime is 21115430563. The next prime is 21115430573. The reversal of 21115430571 is 17503451112.

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 21115430571 - 2³ = 21115430563 is a prime.

It is a super-2 number, since 2×21115430571² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21115430573) 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, 4056 + ... + 205541.

It is an arithmetic number, because the mean of its divisors is an integer number (3519360018).

Almost surely, 2^21115430571 is an apocalyptic number.

21115430571 is a deficient number, since it is larger than the sum of its proper divisors (7039449573).

21115430571 is a wasteful number, since it uses less digits than its factorization.

21115430571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243181.

The product of its (nonzero) digits is 4200, while the sum is 30.

Adding to 21115430571 its reverse (17503451112), we get a palindrome (38618881683).

The spelling of 21115430571 in words is "twenty-one billion, one hundred fifteen million, four hundred thirty thousand, five hundred seventy-one".