21284190 has 48 divisors (see below), whose sum is σ = 55699488. Its totient is φ = 5638848.

The previous prime is 21284189. The next prime is 21284227. The reversal of 21284190 is 9148212.

It is a super-2 number, since 2×21284190² = 906033487912200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14887 + ... + 16253.

It is an arithmetic number, because the mean of its divisors is an integer number (1160406).

Almost surely, 2^21284190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21284190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27849744).

21284190 is an abundant number, since it is smaller than the sum of its proper divisors (34415298).

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

21284190 is a wasteful number, since it uses less digits than its factorization.

21284190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1553 (or 1550 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21284190 is about 4613.4791643618. The cubic root of 21284190 is about 277.1313829775.

The spelling of 21284190 in words is "twenty-one million, two hundred eighty-four thousand, one hundred ninety".