21011418 has 24 divisors (see below), whose sum is σ = 45645600. Its totient is φ = 6985224.

The previous prime is 21011413. The next prime is 21011423. The reversal of 21011418 is 81411012.

It is an interprime number because it is at equal distance from previous prime (21011413) and next prime (21011423).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21011418.

It is not an unprimeable number, because it can be changed into a prime (21011411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6573 + ... + 9231.

It is an arithmetic number, because the mean of its divisors is an integer number (1901900).

Almost surely, 2^21011418 is an apocalyptic number.

21011418 is an abundant number, since it is smaller than the sum of its proper divisors (24634182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011418 is a wasteful number, since it uses less digits than its factorization.

21011418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3106 (or 3103 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 21011418 is about 4583.8213315966. The cubic root of 21011418 is about 275.9424107948.

It can be divided in two parts, 210 and 11418, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 21011418 in words is "twenty-one million, eleven thousand, four hundred eighteen".