21734641 has 4 divisors (see below), whose sum is σ = 21744112. Its totient is φ = 21725172.

The previous prime is 21734621. The next prime is 21734681. The reversal of 21734641 is 14643712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21734641 - 2⁹ = 21734129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21734621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1126 + ... + 6688.

It is an arithmetic number, because the mean of its divisors is an integer number (5436028).

Almost surely, 2^21734641 is an apocalyptic number.

It is an amenable number.

21734641 is a deficient number, since it is larger than the sum of its proper divisors (9471).

21734641 is an equidigital number, since it uses as much as digits as its factorization.

21734641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9470.

The product of its digits is 4032, while the sum is 28.

The square root of 21734641 is about 4662.0425780981. The cubic root of 21734641 is about 279.0727875420.

The spelling of 21734641 in words is "twenty-one million, seven hundred thirty-four thousand, six hundred forty-one".