21655055455625 has 10 divisors (see below), whose sum is σ = 27060157298130. Its totient is φ = 17324044364000.

The previous prime is 21655055455609. The next prime is 21655055455633. The reversal of 21655055455625 is 52655455055612.

It can be written as a sum of positive squares in 5 ways, for example, as 11607049375744 + 10048006079881 = 3406912^2 + 3169859^2 .

It is not a de Polignac number, because 21655055455625 - 2⁴ = 21655055455609 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 17324043740 + ... + 17324044989.

It is an arithmetic number, because the mean of its divisors is an integer number (2706015729813).

Almost surely, 2^{21655055455625} is an apocalyptic number.

21655055455625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21655055455625 is a deficient number, since it is larger than the sum of its proper divisors (5405101842505).

21655055455625 is an frugal number, since it uses more digits than its factorization.

21655055455625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34648088749 (or 34648088734 counting only the distinct ones).

The product of its (nonzero) digits is 45000000, while the sum is 56.

The spelling of 21655055455625 in words is "twenty-one trillion, six hundred fifty-five billion, fifty-five million, four hundred fifty-five thousand, six hundred twenty-five".