21647130 has 16 divisors (see below), whose sum is σ = 51953184. Its totient is φ = 5772560.

The previous prime is 21647113. The next prime is 21647173. The reversal of 21647130 is 3174612.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 21647130.

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, 360756 + ... + 360815.

It is an arithmetic number, because the mean of its divisors is an integer number (3247074).

Almost surely, 2^21647130 is an apocalyptic number.

21647130 is an abundant number, since it is smaller than the sum of its proper divisors (30306054).

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

21647130 is a wasteful number, since it uses less digits than its factorization.

21647130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721581.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21647130 is about 4652.6476333374. The cubic root of 21647130 is about 278.6977366541.

The spelling of 21647130 in words is "twenty-one million, six hundred forty-seven thousand, one hundred thirty".