21241230551 has 4 divisors (see below), whose sum is σ = 21381901104. Its totient is φ = 21100560000.

The previous prime is 21241230539. The next prime is 21241230599. The reversal of 21241230551 is 15503214212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21241230551 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 21241230551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241230851) 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 3 ways as a sum of consecutive naturals, for example, 70335050 + ... + 70335351.

It is an arithmetic number, because the mean of its divisors is an integer number (5345475276).

Almost surely, 2^21241230551 is an apocalyptic number.

21241230551 is a deficient number, since it is larger than the sum of its proper divisors (140670553).

21241230551 is a wasteful number, since it uses less digits than its factorization.

21241230551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140670552.

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

Adding to 21241230551 its reverse (15503214212), we get a palindrome (36744444763).

The spelling of 21241230551 in words is "twenty-one billion, two hundred forty-one million, two hundred thirty thousand, five hundred fifty-one".