21486771 has 6 divisors (see below), whose sum is σ = 31036460. Its totient is φ = 14324508.

The previous prime is 21486737. The next prime is 21486779. The reversal of 21486771 is 17768412.

It is not a de Polignac number, because 21486771 - 2¹⁰ = 21485747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21486779) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1193701 + ... + 1193718.

Almost surely, 2^21486771 is an apocalyptic number.

21486771 is a deficient number, since it is larger than the sum of its proper divisors (9549689).

21486771 is a wasteful number, since it uses less digits than its factorization.

21486771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2387425 (or 2387422 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 21486771 is about 4635.3825084884. The cubic root of 21486771 is about 278.0078453007.

The spelling of 21486771 in words is "twenty-one million, four hundred eighty-six thousand, seven hundred seventy-one".