21621554635351 has 8 divisors (see below), whose sum is σ = 23587324395264. Its totient is φ = 19655813856120.

The previous prime is 21621554635337. The next prime is 21621554635381. The reversal of 21621554635351 is 15353645512612.

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

It is a cyclic number.

It is not a de Polignac number, because 21621554635351 - 2¹³ = 21621554627159 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21621554635295 and 21621554635304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621554635301) 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, 5670321 + ... + 8683066.

It is an arithmetic number, because the mean of its divisors is an integer number (2948415549408).

Almost surely, 2^{21621554635351} is an apocalyptic number.

21621554635351 is a deficient number, since it is larger than the sum of its proper divisors (1965769759913).

21621554635351 is a wasteful number, since it uses less digits than its factorization.

21621554635351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14490341.

The product of its digits is 3240000, while the sum is 49.

The spelling of 21621554635351 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred fifty-four million, six hundred thirty-five thousand, three hundred fifty-one".