21258970 has 16 divisors (see below), whose sum is σ = 38320128. Its totient is φ = 8491600.

The previous prime is 21258917. The next prime is 21258973. The reversal of 21258970 is 7985212.

It is not an unprimeable number, because it can be changed into a prime (21258973) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 10587 + ... + 12433.

It is an arithmetic number, because the mean of its divisors is an integer number (2395008).

Almost surely, 2^21258970 is an apocalyptic number.

21258970 is a deficient number, since it is larger than the sum of its proper divisors (17061158).

21258970 is a wasteful number, since it uses less digits than its factorization.

21258970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3005.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 21258970 is about 4610.7450590984. The cubic root of 21258970 is about 277.0218804804.

The spelling of 21258970 in words is "twenty-one million, two hundred fifty-eight thousand, nine hundred seventy".