21985158 has 32 divisors (see below), whose sum is σ = 47531232. Its totient is φ = 6739200.

The previous prime is 21985153. The next prime is 21985189. The reversal of 21985158 is 85158912.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21985151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40368 + ... + 40908.

It is an arithmetic number, because the mean of its divisors is an integer number (1485351).

Almost surely, 2^21985158 is an apocalyptic number.

21985158 is an abundant number, since it is smaller than the sum of its proper divisors (25546074).

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

21985158 is a wasteful number, since it uses less digits than its factorization.

21985158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its digits is 28800, while the sum is 39.

The square root of 21985158 is about 4688.8333303712. The cubic root of 21985158 is about 280.1409069694.

The spelling of 21985158 in words is "twenty-one million, nine hundred eighty-five thousand, one hundred fifty-eight".