21624621321251 has 12 divisors (see below), whose sum is σ = 23483491430472. Its totient is φ = 19903663817856.

The previous prime is 21624621321241. The next prime is 21624621321313. The reversal of 21624621321251 is 15212312642612.

It is not a de Polignac number, because 21624621321251 - 2³⁰ = 21623547579427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21624621321241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 184316486 + ... + 184433771.

It is an arithmetic number, because the mean of its divisors is an integer number (1956957619206).

Almost surely, 2^{21624621321251} is an apocalyptic number.

21624621321251 is a deficient number, since it is larger than the sum of its proper divisors (1858870109221).

21624621321251 is a wasteful number, since it uses less digits than its factorization.

21624621321251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368750630 (or 368750617 counting only the distinct ones).

The product of its digits is 69120, while the sum is 38.

Adding to 21624621321251 its reverse (15212312642612), we get a palindrome (36836933963863).

The spelling of 21624621321251 in words is "twenty-one trillion, six hundred twenty-four billion, six hundred twenty-one million, three hundred twenty-one thousand, two hundred fifty-one".