21011043 has 8 divisors (see below), whose sum is σ = 28036800. Its totient is φ = 13996328.

The previous prime is 21011033. The next prime is 21011063. The reversal of 21011043 is 34011012.

It is a happy number.

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 21011043 - 2²¹ = 18913891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011033) 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, 4168 + ... + 7706.

It is an arithmetic number, because the mean of its divisors is an integer number (3504600).

Almost surely, 2^21011043 is an apocalyptic number.

21011043 is a deficient number, since it is larger than the sum of its proper divisors (7025757).

21011043 is a wasteful number, since it uses less digits than its factorization.

21011043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5521.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21011043 is about 4583.7804266784. The cubic root of 21011043 is about 275.9407691633.

Adding to 21011043 its reverse (34011012), we get a palindrome (55022055).

The spelling of 21011043 in words is "twenty-one million, eleven thousand, forty-three".