21517084 has 12 divisors (see below), whose sum is σ = 37818144. Its totient is φ = 10711904.

The previous prime is 21517073. The next prime is 21517109. The reversal of 21517084 is 48071512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10612 + ... + 12475.

It is an arithmetic number, because the mean of its divisors is an integer number (3151512).

Almost surely, 2^21517084 is an apocalyptic number.

It is an amenable number.

21517084 is a deficient number, since it is larger than the sum of its proper divisors (16301060).

21517084 is a wasteful number, since it uses less digits than its factorization.

21517084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23324 (or 23322 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21517084 is about 4638.6510970324. The cubic root of 21517084 is about 278.1385193782.

Adding to 21517084 its reverse (48071512), we get a palindrome (69588596).

The spelling of 21517084 in words is "twenty-one million, five hundred seventeen thousand, eighty-four".