21517048 has 32 divisors (see below), whose sum is σ = 46395360. Its totient is φ = 9164160.

The previous prime is 21517039. The next prime is 21517051. The reversal of 21517048 is 84071512.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8578 + ... + 10798.

It is an arithmetic number, because the mean of its divisors is an integer number (1449855).

Almost surely, 2^21517048 is an apocalyptic number.

21517048 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21517048 is an abundant number, since it is smaller than the sum of its proper divisors (24878312).

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

21517048 is a wasteful number, since it uses less digits than its factorization.

21517048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2407 (or 2403 counting only the distinct ones).

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

The square root of 21517048 is about 4638.6472165924. The cubic root of 21517048 is about 278.1383642612.

The spelling of 21517048 in words is "twenty-one million, five hundred seventeen thousand, forty-eight".