56721210 has 128 divisors (see below), whose sum is σ = 170311680. Its totient is φ = 11771136.

The previous prime is 56721209. The next prime is 56721211. The reversal of 56721210 is 1212765.

It is an interprime number because it is at equal distance from previous prime (56721209) and next prime (56721211).

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (56721211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 215539 + ... + 215801.

It is an arithmetic number, because the mean of its divisors is an integer number (1330560).

Almost surely, 2^56721210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56721210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85155840).

56721210 is an abundant number, since it is smaller than the sum of its proper divisors (113590470).

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

56721210 is a wasteful number, since it uses less digits than its factorization.

56721210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 56721210 is about 7531.3484848332. The cubic root of 56721210 is about 384.2216466709.

Adding to 56721210 its reverse (1212765), we get a palindrome (57933975).

The spelling of 56721210 in words is "fifty-six million, seven hundred twenty-one thousand, two hundred ten".