21047001 has 8 divisors (see below), whose sum is σ = 29282880. Its totient is φ = 13421232.

The previous prime is 21046997. The next prime is 21047017. The reversal of 21047001 is 10074012.

21047001 is nontrivially palindromic in base 7.

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

It is not a de Polignac number, because 21047001 - 2² = 21046997 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21047051) 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, 152446 + ... + 152583.

It is an arithmetic number, because the mean of its divisors is an integer number (3660360).

Almost surely, 2^21047001 is an apocalyptic number.

It is an amenable number.

21047001 is a deficient number, since it is larger than the sum of its proper divisors (8235879).

21047001 is a wasteful number, since it uses less digits than its factorization.

21047001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305055.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21047001 is about 4587.7010582644. The cubic root of 21047001 is about 276.0980931519.

The spelling of 21047001 in words is "twenty-one million, forty-seven thousand, one".