21074284 has 48 divisors (see below), whose sum is σ = 46884096. Its totient is φ = 8049600.

The previous prime is 21074239. The next prime is 21074311. The reversal of 21074284 is 48247012.

It is a super-2 number, since 2×21074284² = 888250892225312, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15679 + ... + 16969.

It is an arithmetic number, because the mean of its divisors is an integer number (976752).

Almost surely, 2^21074284 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21074284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23442048).

21074284 is an abundant number, since it is smaller than the sum of its proper divisors (25809812).

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

21074284 is a wasteful number, since it uses less digits than its factorization.

21074284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1366 (or 1364 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 21074284 is about 4590.6735889192. The cubic root of 21074284 is about 276.2173426312.

The spelling of 21074284 in words is "twenty-one million, seventy-four thousand, two hundred eighty-four".