21611712 has 56 divisors (see below), whose sum is σ = 59041792. Its totient is φ = 6969600.

The previous prime is 21611693. The next prime is 21611731. The reversal of 21611712 is 21711612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21611693) and next prime (21611731).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4137 + ... + 7767.

Almost surely, 2^21611712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21611712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29520896).

21611712 is an abundant number, since it is smaller than the sum of its proper divisors (37430080).

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

21611712 is a wasteful number, since it uses less digits than its factorization.

21611712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3677 (or 3667 counting only the distinct ones).

The product of its digits is 168, while the sum is 21.

The square root of 21611712 is about 4648.8398552757. The cubic root of 21611712 is about 278.5456563741.

The spelling of 21611712 in words is "twenty-one million, six hundred eleven thousand, seven hundred twelve".