21355353025551 has 12 divisors (see below), whose sum is σ = 30846885937920. Its totient is φ = 14236779755040.

The previous prime is 21355353025519. The next prime is 21355353025577. The reversal of 21355353025551 is 15552035355312.

21355353025551 is a `hidden beast` number, since 2 + 1 + 35 + 5 + 35 + 30 + 2 + 5 + 551 = 666.

It is not a de Polignac number, because 21355353025551 - 2⁵ = 21355353025519 is a prime.

It is a super-2 number, since 2×21355353025551² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21355353025497 and 21355353025506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355353025451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9075870 + ... + 11184011.

It is an arithmetic number, because the mean of its divisors is an integer number (2570573828160).

Almost surely, 2^{21355353025551} is an apocalyptic number.

21355353025551 is a deficient number, since it is larger than the sum of its proper divisors (9491532912369).

21355353025551 is a wasteful number, since it uses less digits than its factorization.

21355353025551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20377006 (or 20377003 counting only the distinct ones).

The product of its (nonzero) digits is 1687500, while the sum is 45.

The spelling of 21355353025551 in words is "twenty-one trillion, three hundred fifty-five billion, three hundred fifty-three million, twenty-five thousand, five hundred fifty-one".