21447330 has 16 divisors (see below), whose sum is σ = 51473664. Its totient is φ = 5719280.

The previous prime is 21447311. The next prime is 21447337. The reversal of 21447330 is 3374412.

It is a self number, because there is not a number n which added to its sum of digits gives 21447330.

It is not an unprimeable number, because it can be changed into a prime (21447337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 357426 + ... + 357485.

It is an arithmetic number, because the mean of its divisors is an integer number (3217104).

Almost surely, 2^21447330 is an apocalyptic number.

21447330 is an abundant number, since it is smaller than the sum of its proper divisors (30026334).

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

21447330 is a wasteful number, since it uses less digits than its factorization.

21447330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714921.

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 21447330 is about 4631.1262129206. The cubic root of 21447330 is about 277.8376378846.

The spelling of 21447330 in words is "twenty-one million, four hundred forty-seven thousand, three hundred thirty".