21083964 has 48 divisors (see below), whose sum is σ = 53993856. Its totient is φ = 6350400.

The previous prime is 21083941. The next prime is 21083989. The reversal of 21083964 is 46938012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27474 + ... + 28230.

It is an arithmetic number, because the mean of its divisors is an integer number (1124872).

Almost surely, 2^21083964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21083964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26996928).

21083964 is an abundant number, since it is smaller than the sum of its proper divisors (32909892).

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

21083964 is a wasteful number, since it uses less digits than its factorization.

21083964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986 (or 984 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21083964 is about 4591.7277793876. The cubic root of 21083964 is about 276.2596275727.

The spelling of 21083964 in words is "twenty-one million, eighty-three thousand, nine hundred sixty-four".