21346528 has 48 divisors (see below), whose sum is σ = 48353760. Its totient is φ = 9086976.

The previous prime is 21346517. The next prime is 21346537. The reversal of 21346528 is 82564312.

It is a self number, because there is not a number n which added to its sum of digits gives 21346528.

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, 51988 + ... + 52396.

It is an arithmetic number, because the mean of its divisors is an integer number (1007370).

Almost surely, 2^21346528 is an apocalyptic number.

21346528 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21346528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24176880).

21346528 is an abundant number, since it is smaller than the sum of its proper divisors (27007232).

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

21346528 is a wasteful number, since it uses less digits than its factorization.

21346528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 659 (or 651 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 21346528 is about 4620.2302972904. The cubic root of 21346528 is about 277.4016771490.

The spelling of 21346528 in words is "twenty-one million, three hundred forty-six thousand, five hundred twenty-eight".