21011018 has 8 divisors (see below), whose sum is σ = 36018912. Its totient is φ = 9004716.

The previous prime is 21011009. The next prime is 21011033. The reversal of 21011018 is 81011012.

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

It is a Harshad number since it is a multiple of its sum of digits (14), and also a Moran number because the ratio is a prime number: 1500787 = 21011018 / (2 + 1 + 0 + 1 + 1 + 0 + 1 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 21010993 and 21011011.

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, 750380 + ... + 750407.

It is an arithmetic number, because the mean of its divisors is an integer number (4502364).

Almost surely, 2^21011018 is an apocalyptic number.

21011018 is a deficient number, since it is larger than the sum of its proper divisors (15007894).

21011018 is a wasteful number, since it uses less digits than its factorization.

21011018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1500796.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 21011018 is about 4583.7776996709. Note that the first 3 decimals coincide. The cubic root of 21011018 is about 275.9406597205.

The spelling of 21011018 in words is "twenty-one million, eleven thousand, eighteen".