21542382 has 16 divisors (see below), whose sum is σ = 47872080. Its totient is φ = 7180776.

The previous prime is 21542377. The next prime is 21542393. The reversal of 21542382 is 28324512.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199413 + ... + 199520.

It is an arithmetic number, because the mean of its divisors is an integer number (2992005).

Almost surely, 2^21542382 is an apocalyptic number.

21542382 is an abundant number, since it is smaller than the sum of its proper divisors (26329698).

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

21542382 is a wasteful number, since it uses less digits than its factorization.

21542382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398944 (or 398938 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21542382 is about 4641.3771663160. The cubic root of 21542382 is about 278.2474807424.

Adding to 21542382 its reverse (28324512), we get a palindrome (49866894).

The spelling of 21542382 in words is "twenty-one million, five hundred forty-two thousand, three hundred eighty-two".