21471330 has 64 divisors (see below), whose sum is σ = 54835200. Its totient is φ = 5365440.

The previous prime is 21471301. The next prime is 21471337. The reversal of 21471330 is 3317412.

It is a super-2 number, since 2×21471330² = 922036023937800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21471297 and 21471306.

It is not an unprimeable number, because it can be changed into a prime (21471337) 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, 79095 + ... + 79365.

It is an arithmetic number, because the mean of its divisors is an integer number (856800).

Almost surely, 2^21471330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21471330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27417600).

21471330 is an abundant number, since it is smaller than the sum of its proper divisors (33363870).

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

21471330 is a wasteful number, since it uses less digits than its factorization.

21471330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21471330 is about 4633.7166508107. The cubic root of 21471330 is about 277.9412345811.

Adding to 21471330 its reverse (3317412), we get a palindrome (24788742).

The spelling of 21471330 in words is "twenty-one million, four hundred seventy-one thousand, three hundred thirty".