55817705025821 has 4 divisors (see below), whose sum is σ = 55818663673500. Its totient is φ = 55816746378144.

The previous prime is 55817705025751. The next prime is 55817705025917. The reversal of 55817705025821 is 12852050771855.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39144480468025 + 16673224557796 = 6256555^2 + 4083286^2 .

It is a cyclic number.

It is not a de Polignac number, because 55817705025821 - 2⁴² = 51419658514717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55817705025721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 479236496 + ... + 479352953.

It is an arithmetic number, because the mean of its divisors is an integer number (13954665918375).

Almost surely, 2^{55817705025821} is an apocalyptic number.

It is an amenable number.

55817705025821 is a deficient number, since it is larger than the sum of its proper divisors (958647679).

55817705025821 is an equidigital number, since it uses as much as digits as its factorization.

55817705025821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958647678.

The product of its (nonzero) digits is 7840000, while the sum is 56.

The spelling of 55817705025821 in words is "fifty-five trillion, eight hundred seventeen billion, seven hundred five million, twenty-five thousand, eight hundred twenty-one".