21071958 has 8 divisors (see below), whose sum is σ = 42143928. Its totient is φ = 7023984.

The previous prime is 21071927. The next prime is 21071977. The reversal of 21071958 is 85917012.

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

21071958 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1755991 + ... + 1756002.

It is an arithmetic number, because the mean of its divisors is an integer number (5267991).

Almost surely, 2^21071958 is an apocalyptic number.

21071958 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21071958 is a wasteful number, since it uses less digits than its factorization.

21071958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3511998.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 21071958 is about 4590.4202422001. The cubic root of 21071958 is about 276.2071800846.

The spelling of 21071958 in words is "twenty-one million, seventy-one thousand, nine hundred fifty-eight".