21461610 has 64 divisors (see below), whose sum is σ = 54411264. Its totient is φ = 5409600.

The previous prime is 21461593. The next prime is 21461611. The reversal of 21461610 is 1616412.

It is not an unprimeable number, because it can be changed into a prime (21461611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43465 + ... + 43955.

It is an arithmetic number, because the mean of its divisors is an integer number (850176).

Almost surely, 2^21461610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21461610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27205632).

21461610 is an abundant number, since it is smaller than the sum of its proper divisors (32949654).

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

21461610 is a wasteful number, since it uses less digits than its factorization.

21461610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21461610 is about 4632.6676979900. The cubic root of 21461610 is about 277.8992872251.

The spelling of 21461610 in words is "twenty-one million, four hundred sixty-one thousand, six hundred ten".