21487158 has 96 divisors (see below), whose sum is σ = 59754240. Its totient is φ = 5417280.

The previous prime is 21487153. The next prime is 21487171. The reversal of 21487158 is 85178412.

21487158 is a `hidden beast` number, since 21 + 487 + 158 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21487153) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51073 + ... + 51491.

It is an arithmetic number, because the mean of its divisors is an integer number (622440).

Almost surely, 2^21487158 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21487158, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29877120).

21487158 is an abundant number, since it is smaller than the sum of its proper divisors (38267082).

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

21487158 is a wasteful number, since it uses less digits than its factorization.

21487158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482 (or 479 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 21487158 is about 4635.4242524282. The cubic root of 21487158 is about 278.0095143648.

The spelling of 21487158 in words is "twenty-one million, four hundred eighty-seven thousand, one hundred fifty-eight".