21711450 has 48 divisors (see below), whose sum is σ = 54880416. Its totient is φ = 5678400.

The previous prime is 21711421. The next prime is 21711451. The reversal of 21711450 is 5411712.

It is a happy number.

It is a super-2 number, since 2×21711450² = 942774122205000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21711451) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6585 + ... + 9315.

It is an arithmetic number, because the mean of its divisors is an integer number (1143342).

Almost surely, 2^21711450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21711450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27440208).

21711450 is an abundant number, since it is smaller than the sum of its proper divisors (33168966).

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

21711450 is a wasteful number, since it uses less digits than its factorization.

21711450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2799 (or 2794 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 21711450 is about 4659.5546997540. The cubic root of 21711450 is about 278.9734947393.

The spelling of 21711450 in words is "twenty-one million, seven hundred eleven thousand, four hundred fifty".