21252334551 has 8 divisors (see below), whose sum is σ = 32384509824. Its totient is φ = 12144191160.

The previous prime is 21252334531. The next prime is 21252334589. The reversal of 21252334551 is 15543325212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21252334551 - 2¹⁴ = 21252318167 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21252334531) 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, 506007945 + ... + 506007986.

It is an arithmetic number, because the mean of its divisors is an integer number (4048063728).

Almost surely, 2^21252334551 is an apocalyptic number.

21252334551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21252334551 is a deficient number, since it is larger than the sum of its proper divisors (11132175273).

21252334551 is a wasteful number, since it uses less digits than its factorization.

21252334551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012015941.

The product of its digits is 36000, while the sum is 33.

Adding to 21252334551 its reverse (15543325212), we get a palindrome (36795659763).

The spelling of 21252334551 in words is "twenty-one billion, two hundred fifty-two million, three hundred thirty-four thousand, five hundred fifty-one".