55821340 has 24 divisors (see below), whose sum is σ = 117366480. Its totient is φ = 22301568.

The previous prime is 55821323. The next prime is 55821341. The reversal of 55821340 is 4312855.

It is a junction number, because it is equal to n+sod(n) for n = 55821299 and 55821308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55821341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28224 + ... + 30136.

It is an arithmetic number, because the mean of its divisors is an integer number (4890270).

Almost surely, 2^55821340 is an apocalyptic number.

It is an amenable number.

55821340 is an abundant number, since it is smaller than the sum of its proper divisors (61545140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55821340 is a wasteful number, since it uses less digits than its factorization.

55821340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3381 (or 3379 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 55821340 is about 7471.3680139584. The cubic root of 55821340 is about 382.1789408631.

The spelling of 55821340 in words is "fifty-five million, eight hundred twenty-one thousand, three hundred forty".