21011258 has 8 divisors (see below), whose sum is σ = 31549728. Its totient is φ = 10494684.

The previous prime is 21011251. The next prime is 21011293. The reversal of 21011258 is 85211012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21011251) 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 3 ways as a sum of consecutive naturals, for example, 2816 + ... + 7067.

It is an arithmetic number, because the mean of its divisors is an integer number (3943716).

Almost surely, 2^21011258 is an apocalyptic number.

21011258 is a deficient number, since it is larger than the sum of its proper divisors (10538470).

21011258 is a wasteful number, since it uses less digits than its factorization.

21011258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10948.

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 21011258 is about 4583.8038788761. The cubic root of 21011258 is about 275.9417103677.

The spelling of 21011258 in words is "twenty-one million, eleven thousand, two hundred fifty-eight".