21845487 has 8 divisors (see below), whose sum is σ = 29677104. Its totient is φ = 14288768.

The previous prime is 21845471. The next prime is 21845489. The reversal of 21845487 is 78454812.

It is a happy number.

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 21845487 - 2⁴ = 21845471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21845489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68538 + ... + 68855.

It is an arithmetic number, because the mean of its divisors is an integer number (3709638).

Almost surely, 2^21845487 is an apocalyptic number.

21845487 is a deficient number, since it is larger than the sum of its proper divisors (7831617).

21845487 is a wasteful number, since it uses less digits than its factorization.

21845487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137449.

The product of its digits is 71680, while the sum is 39.

The square root of 21845487 is about 4673.9155961570. The cubic root of 21845487 is about 279.5464041838.

The spelling of 21845487 in words is "twenty-one million, eight hundred forty-five thousand, four hundred eighty-seven".