21328970 has 32 divisors (see below), whose sum is σ = 41610240. Its totient is φ = 7824960.

The previous prime is 21328969. The next prime is 21328987. The reversal of 21328970 is 7982312.

It is a super-2 number, since 2×21328970² = 909849922521800, which contains 22 as substring.

It is a Curzon number.

It is a zygodrome in base 9.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24401 + ... + 25259.

It is an arithmetic number, because the mean of its divisors is an integer number (1300320).

Almost surely, 2^21328970 is an apocalyptic number.

21328970 is a deficient number, since it is larger than the sum of its proper divisors (20281270).

21328970 is a wasteful number, since it uses less digits than its factorization.

21328970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1070.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 21328970 is about 4618.3297846732. The cubic root of 21328970 is about 277.3255999112.

The spelling of 21328970 in words is "twenty-one million, three hundred twenty-eight thousand, nine hundred seventy".