21165371441 has 8 divisors (see below), whose sum is σ = 21283553760. Its totient is φ = 21047277312.

The previous prime is 21165371419. The next prime is 21165371471. The reversal of 21165371441 is 14417356112.

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-21165371441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21165371471) 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, 492566 + ... + 533808.

It is an arithmetic number, because the mean of its divisors is an integer number (2660444220).

Almost surely, 2^21165371441 is an apocalyptic number.

It is an amenable number.

21165371441 is a deficient number, since it is larger than the sum of its proper divisors (118182319).

21165371441 is a wasteful number, since it uses less digits than its factorization.

21165371441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44095.

The product of its digits is 20160, while the sum is 35.

The spelling of 21165371441 in words is "twenty-one billion, one hundred sixty-five million, three hundred seventy-one thousand, four hundred forty-one".