21005443151 has 32 divisors (see below), whose sum is σ = 28934765568. Its totient is φ = 14735255040.

The previous prime is 21005443133. The next prime is 21005443157. The reversal of 21005443151 is 15134450012.

It is not a de Polignac number, because 21005443151 - 2¹⁰ = 21005442127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21005443151.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005443157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 318740 + ... + 378953.

It is an arithmetic number, because the mean of its divisors is an integer number (904211424).

Almost surely, 2^21005443151 is an apocalyptic number.

21005443151 is a deficient number, since it is larger than the sum of its proper divisors (7929322417).

21005443151 is a wasteful number, since it uses less digits than its factorization.

21005443151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697751.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21005443151 its reverse (15134450012), we get a palindrome (36139893163).

The spelling of 21005443151 in words is "twenty-one billion, five million, four hundred forty-three thousand, one hundred fifty-one".