21850487 has 4 divisors (see below), whose sum is σ = 21908520. Its totient is φ = 21792456.

The previous prime is 21850453. The next prime is 21850489. The reversal of 21850487 is 78405812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21850487 - 2¹⁰ = 21849463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21850489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28448 + ... + 29205.

It is an arithmetic number, because the mean of its divisors is an integer number (5477130).

Almost surely, 2^21850487 is an apocalyptic number.

21850487 is a deficient number, since it is larger than the sum of its proper divisors (58033).

21850487 is an equidigital number, since it uses as much as digits as its factorization.

21850487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58032.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 21850487 is about 4674.4504489833. The cubic root of 21850487 is about 279.5677301049.

It can be divided in two parts, 218 and 50487, that added together give a palindrome (50705).

The spelling of 21850487 in words is "twenty-one million, eight hundred fifty thousand, four hundred eighty-seven".