21451604110155 has 24 divisors (see below), whose sum is σ = 37182890620512. Its totient is φ = 11440821629184.

The previous prime is 21451604110141. The next prime is 21451604110199. The reversal of 21451604110155 is 55101140615412.

21451604110155 is a `hidden beast` number, since 2 + 1 + 45 + 1 + 604 + 1 + 1 + 0 + 1 + 5 + 5 = 666.

It is not a de Polignac number, because 21451604110155 - 2⁹ = 21451604109643 is a prime.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 24679507 + ... + 25533923.

It is an arithmetic number, because the mean of its divisors is an integer number (1549287109188).

Almost surely, 2^{21451604110155} is an apocalyptic number.

21451604110155 is a deficient number, since it is larger than the sum of its proper divisors (15731286510357).

21451604110155 is a wasteful number, since it uses less digits than its factorization.

21451604110155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1412355 (or 1412352 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 36.

Adding to 21451604110155 its reverse (55101140615412), we get a palindrome (76552744725567).

The spelling of 21451604110155 in words is "twenty-one trillion, four hundred fifty-one billion, six hundred four million, one hundred ten thousand, one hundred fifty-five".