56821830 has 64 divisors (see below), whose sum is σ = 149688000. Its totient is φ = 13718016.

The previous prime is 56821819. The next prime is 56821861. The reversal of 56821830 is 3812865.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 56821791 and 56821800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19296 + ... + 22044.

It is an arithmetic number, because the mean of its divisors is an integer number (2338875).

Almost surely, 2^56821830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56821830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74844000).

56821830 is an abundant number, since it is smaller than the sum of its proper divisors (92866170).

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

56821830 is a wasteful number, since it uses less digits than its factorization.

56821830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2825.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 56821830 is about 7538.0256035649. The cubic root of 56821830 is about 384.4487077897.

The spelling of 56821830 in words is "fifty-six million, eight hundred twenty-one thousand, eight hundred thirty".