21207043 has 8 divisors (see below), whose sum is σ = 24914736. Its totient is φ = 17796000.

The previous prime is 21207037. The next prime is 21207101. The reversal of 21207043 is 34070212.

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

It is a cyclic number.

It is not a de Polignac number, because 21207043 - 2²¹ = 19109891 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21207043.

It is not an unprimeable number, because it can be changed into a prime (21205043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74008 + ... + 74293.

It is an arithmetic number, because the mean of its divisors is an integer number (3114342).

Almost surely, 2^21207043 is an apocalyptic number.

21207043 is a deficient number, since it is larger than the sum of its proper divisors (3707693).

21207043 is a wasteful number, since it uses less digits than its factorization.

21207043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148325.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21207043 is about 4605.1105307039. The cubic root of 21207043 is about 276.7961460686.

Adding to 21207043 its reverse (34070212), we get a palindrome (55277255).

The spelling of 21207043 in words is "twenty-one million, two hundred seven thousand, forty-three".