21871598 has 16 divisors (see below), whose sum is σ = 37601280. Its totient is φ = 9346776.

The previous prime is 21871589. The next prime is 21871609. The reversal of 21871598 is 89517812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3323 + ... + 7401.

It is an arithmetic number, because the mean of its divisors is an integer number (2350080).

Almost surely, 2^21871598 is an apocalyptic number.

21871598 is a deficient number, since it is larger than the sum of its proper divisors (15729682).

21871598 is a wasteful number, since it uses less digits than its factorization.

21871598 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4471.

The product of its digits is 40320, while the sum is 41.

The square root of 21871598 is about 4676.7080302281. The cubic root of 21871598 is about 279.6577365600.

The spelling of 21871598 in words is "twenty-one million, eight hundred seventy-one thousand, five hundred ninety-eight".