21254421511 has 8 divisors (see below), whose sum is σ = 21315773024. Its totient is φ = 21193159680.

The previous prime is 21254421491. The next prime is 21254421541. The reversal of 21254421511 is 11512445212.

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-21254421511 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 21254421511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254421541) 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 7 ways as a sum of consecutive naturals, for example, 467551 + ... + 510991.

It is an arithmetic number, because the mean of its divisors is an integer number (2664471628).

Almost surely, 2^21254421511 is an apocalyptic number.

21254421511 is a deficient number, since it is larger than the sum of its proper divisors (61351513).

21254421511 is an equidigital number, since it uses as much as digits as its factorization.

21254421511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44841.

The product of its digits is 3200, while the sum is 28.

Adding to 21254421511 its reverse (11512445212), we get a palindrome (32766866723).

It can be divided in two parts, 2125442 and 1511, that added together give a triangular number (2126953 = T₂₀₆₂).

The spelling of 21254421511 in words is "twenty-one billion, two hundred fifty-four million, four hundred twenty-one thousand, five hundred eleven".