21588742 has 16 divisors (see below), whose sum is σ = 39186720. Its totient is φ = 8707968.

The previous prime is 21588739. The next prime is 21588781. The reversal of 21588742 is 24788512.

It is a super-2 number, since 2×21588742² = 932147562285128, which contains 22 as substring.

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, 45117 + ... + 45592.

It is an arithmetic number, because the mean of its divisors is an integer number (2449170).

Almost surely, 2^21588742 is an apocalyptic number.

21588742 is a deficient number, since it is larger than the sum of its proper divisors (17597978).

21588742 is a wasteful number, since it uses less digits than its factorization.

21588742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90735.

The product of its digits is 35840, while the sum is 37.

The square root of 21588742 is about 4646.3686896328. The cubic root of 21588742 is about 278.4469373425.

The spelling of 21588742 in words is "twenty-one million, five hundred eighty-eight thousand, seven hundred forty-two".