21973528 has 32 divisors (see below), whose sum is σ = 42134400. Its totient is φ = 10741248.

The previous prime is 21973463. The next prime is 21973529. The reversal of 21973528 is 82537912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21973529) by changing a digit.

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, 98425 + ... + 98647.

It is an arithmetic number, because the mean of its divisors is an integer number (1316700).

Almost surely, 2^21973528 is an apocalyptic number.

It is an amenable number.

21973528 is a deficient number, since it is larger than the sum of its proper divisors (20160872).

21973528 is a wasteful number, since it uses less digits than its factorization.

21973528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 447 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The square root of 21973528 is about 4687.5929857444. The cubic root of 21973528 is about 280.0915007076.

The spelling of 21973528 in words is "twenty-one million, nine hundred seventy-three thousand, five hundred twenty-eight".