21047793 has 8 divisors (see below), whose sum is σ = 30222528. Its totient is φ = 12952464.

The previous prime is 21047777. The next prime is 21047813. The reversal of 21047793 is 39774012.

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

It is not a de Polignac number, because 21047793 - 2⁴ = 21047777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21047713) 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, 269805 + ... + 269882.

It is an arithmetic number, because the mean of its divisors is an integer number (3777816).

Almost surely, 2^21047793 is an apocalyptic number.

It is an amenable number.

21047793 is a deficient number, since it is larger than the sum of its proper divisors (9174735).

21047793 is a wasteful number, since it uses less digits than its factorization.

21047793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539703.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 21047793 is about 4587.7873751951. The cubic root of 21047793 is about 276.1015563048.

The spelling of 21047793 in words is "twenty-one million, forty-seven thousand, seven hundred ninety-three".