21487801 has 8 divisors (see below), whose sum is σ = 21749024. Its totient is φ = 21228480.

The previous prime is 21487783. The next prime is 21487891. The reversal of 21487801 is 10878412.

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 21487801 - 2⁷ = 21487673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21487891) 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, 39010 + ... + 39556.

It is an arithmetic number, because the mean of its divisors is an integer number (2718628).

Almost surely, 2^21487801 is an apocalyptic number.

It is an amenable number.

21487801 is a deficient number, since it is larger than the sum of its proper divisors (261223).

21487801 is a wasteful number, since it uses less digits than its factorization.

21487801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 951.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 21487801 is about 4635.4936090993. The cubic root of 21487801 is about 278.0122874682.

The spelling of 21487801 in words is "twenty-one million, four hundred eighty-seven thousand, eight hundred one".