21284632 has 8 divisors (see below), whose sum is σ = 39908700. Its totient is φ = 10642312.

The previous prime is 21284621. The next prime is 21284671. The reversal of 21284632 is 23648212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21284632.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330282 + ... + 1330297.

Almost surely, 2^21284632 is an apocalyptic number.

It is an amenable number.

21284632 is a deficient number, since it is larger than the sum of its proper divisors (18624068).

21284632 is a wasteful number, since it uses less digits than its factorization.

21284632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660585 (or 2660581 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 21284632 is about 4613.5270672231. The cubic root of 21284632 is about 277.1333013219.

It can be divided in two parts, 212846 and 32, that added together give a triangular number (212878 = T₆₅₂).

The spelling of 21284632 in words is "twenty-one million, two hundred eighty-four thousand, six hundred thirty-two".