21017052 has 36 divisors (see below), whose sum is σ = 60716656. Its totient is φ = 6004800.

The previous prime is 21017027. The next prime is 21017063. The reversal of 21017052 is 25071012.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 11 ways as a sum of consecutive naturals, for example, 41449 + ... + 41952.

Almost surely, 2^21017052 is an apocalyptic number.

It is an amenable number.

21017052 is an abundant number, since it is smaller than the sum of its proper divisors (39699604).

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

21017052 is a wasteful number, since it uses less digits than its factorization.

21017052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83418 (or 83413 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 21017052 is about 4584.4358431545. The cubic root of 21017052 is about 275.9670723163.

Adding to 21017052 its reverse (25071012), we get a palindrome (46088064).

The spelling of 21017052 in words is "twenty-one million, seventeen thousand, fifty-two".