55860821 has 4 divisors (see below), whose sum is σ = 56568000. Its totient is φ = 55153644.

The previous prime is 55860751. The next prime is 55860829. The reversal of 55860821 is 12806855.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55860821 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 (55860829) 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, 353471 + ... + 353628.

It is an arithmetic number, because the mean of its divisors is an integer number (14142000).

Almost surely, 2^55860821 is an apocalyptic number.

It is an amenable number.

55860821 is a deficient number, since it is larger than the sum of its proper divisors (707179).

55860821 is an equidigital number, since it uses as much as digits as its factorization.

55860821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707178.

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 55860821 is about 7474.0097002881. The cubic root of 55860821 is about 382.2690214121.

The spelling of 55860821 in words is "fifty-five million, eight hundred sixty thousand, eight hundred twenty-one".