21136958 has 4 divisors (see below), whose sum is σ = 31705440. Its totient is φ = 10568478.

The previous prime is 21136937. The next prime is 21136963. The reversal of 21136958 is 85963112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 5284238 + ... + 5284241.

It is an arithmetic number, because the mean of its divisors is an integer number (7926360).

Almost surely, 2^21136958 is an apocalyptic number.

21136958 is a deficient number, since it is larger than the sum of its proper divisors (10568482).

21136958 is a wasteful number, since it uses less digits than its factorization.

21136958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10568481.

The product of its digits is 12960, while the sum is 35.

The square root of 21136958 is about 4597.4947525799. The cubic root of 21136958 is about 276.4908910733.

The spelling of 21136958 in words is "twenty-one million, one hundred thirty-six thousand, nine hundred fifty-eight".