21011148 has 36 divisors (see below), whose sum is σ = 53278680. Its totient is φ = 6981696.

The previous prime is 21011143. The next prime is 21011173. The reversal of 21011148 is 84111012.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21011148.

It is not an unprimeable number, because it can be changed into a prime (21011141) 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, 14011 + ... + 15437.

Almost surely, 2^21011148 is an apocalyptic number.

It is an amenable number.

21011148 is an abundant number, since it is smaller than the sum of its proper divisors (32267532).

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

21011148 is a wasteful number, since it uses less digits than its factorization.

21011148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1846 (or 1841 counting only the distinct ones).

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

The square root of 21011148 is about 4583.7918800923. The cubic root of 21011148 is about 275.9412288221.

It can be divided in two parts, 2101 and 1148, that added together give a square (3249 = 57²).

The spelling of 21011148 in words is "twenty-one million, eleven thousand, one hundred forty-eight".