21232387 has 8 divisors (see below), whose sum is σ = 23197680. Its totient is φ = 19272960.

The previous prime is 21232373. The next prime is 21232399. The reversal of 21232387 is 78323212.

21232387 is nontrivially palindromic in base 12.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21232387 - 2⁷ = 21232259 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a pancake number, because a pancake can be divided into 21232387 parts by 6516 straight cuts.

It is not an unprimeable number, because it can be changed into a prime (21232307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10143 + ... + 12055.

It is an arithmetic number, because the mean of its divisors is an integer number (2899710).

Almost surely, 2^21232387 is an apocalyptic number.

21232387 is a deficient number, since it is larger than the sum of its proper divisors (1965293).

21232387 is a wasteful number, since it uses less digits than its factorization.

21232387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2933.

The product of its digits is 4032, while the sum is 28.

The square root of 21232387 is about 4607.8614345486. The cubic root of 21232387 is about 276.9063661945.

Adding to 21232387 its reverse (78323212), we get a palindrome (99555599).

The spelling of 21232387 in words is "twenty-one million, two hundred thirty-two thousand, three hundred eighty-seven".