21235452671 has 4 divisors (see below), whose sum is σ = 21258312000. Its totient is φ = 21212593344.

The previous prime is 21235452659. The next prime is 21235452677. The reversal of 21235452671 is 17625453212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21235452671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235452677) 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 3 ways as a sum of consecutive naturals, for example, 11428271 + ... + 11430128.

It is an arithmetic number, because the mean of its divisors is an integer number (5314578000).

Almost surely, 2^21235452671 is an apocalyptic number.

21235452671 is a deficient number, since it is larger than the sum of its proper divisors (22859329).

21235452671 is an equidigital number, since it uses as much as digits as its factorization.

21235452671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22859328.

The product of its digits is 100800, while the sum is 38.

The spelling of 21235452671 in words is "twenty-one billion, two hundred thirty-five million, four hundred fifty-two thousand, six hundred seventy-one".