21255032051 has 16 divisors (see below), whose sum is σ = 24555934080. Its totient is φ = 18182666880.

The previous prime is 21255032027. The next prime is 21255032059. The reversal of 21255032051 is 15023055212.

It is not a de Polignac number, because 21255032051 - 2¹⁰ = 21255031027 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 21255032051.

It is not an unprimeable number, because it can be changed into a prime (21255032059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1687760 + ... + 1700306.

It is an arithmetic number, because the mean of its divisors is an integer number (1534745880).

Almost surely, 2^21255032051 is an apocalyptic number.

21255032051 is a deficient number, since it is larger than the sum of its proper divisors (3300902029).

21255032051 is a wasteful number, since it uses less digits than its factorization.

21255032051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21634.

The product of its (nonzero) digits is 3000, while the sum is 26.

Adding to 21255032051 its reverse (15023055212), we get a palindrome (36278087263).

The spelling of 21255032051 in words is "twenty-one billion, two hundred fifty-five million, thirty-two thousand, fifty-one".