21551442104025 has 18 divisors (see below), whose sum is σ = 38601027413390. Its totient is φ = 11494102455360.

The previous prime is 21551442103979. The next prime is 21551442104057. The reversal of 21551442104025 is 52040124415512.

21551442104025 is a `hidden beast` number, since 2 + 1 + 551 + 4 + 42 + 1 + 0 + 40 + 25 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 8773881561 + 21542668222464 = 93669^2 + 4641408^2 .

It is not a de Polignac number, because 21551442104025 - 2¹⁰ = 21551442103001 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 17 ways as a sum of consecutive naturals, for example, 47892093340 + ... + 47892093789.

Almost surely, 2^{21551442104025} is an apocalyptic number.

21551442104025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21551442104025 is a deficient number, since it is larger than the sum of its proper divisors (17049585309365).

21551442104025 is a wasteful number, since it uses less digits than its factorization.

21551442104025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95784187145 (or 95784187137 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 36.

Adding to 21551442104025 its reverse (52040124415512), we get a palindrome (73591566519537).

The spelling of 21551442104025 in words is "twenty-one trillion, five hundred fifty-one billion, four hundred forty-two million, one hundred four thousand, twenty-five".