21487161 has 8 divisors (see below), whose sum is σ = 28682784. Its totient is φ = 14308160.

The previous prime is 21487153. The next prime is 21487171. The reversal of 21487161 is 16178412.

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 21487161 - 2³ = 21487153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21487111) 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, 735 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (3585348).

Almost surely, 2^21487161 is an apocalyptic number.

It is an amenable number.

21487161 is a deficient number, since it is larger than the sum of its proper divisors (7195623).

21487161 is an equidigital number, since it uses as much as digits as its factorization.

21487161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8311.

The product of its digits is 2688, while the sum is 30.

The square root of 21487161 is about 4635.4245760232. The cubic root of 21487161 is about 278.0095273032.

The spelling of 21487161 in words is "twenty-one million, four hundred eighty-seven thousand, one hundred sixty-one".