21716771 has 8 divisors (see below), whose sum is σ = 22514688. Its totient is φ = 20925000.

The previous prime is 21716767. The next prime is 21716809. The reversal of 21716771 is 17761712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21716771 - 2² = 21716767 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21716731) 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, 6386 + ... + 9176.

It is an arithmetic number, because the mean of its divisors is an integer number (2814336).

Almost surely, 2^21716771 is an apocalyptic number.

21716771 is a deficient number, since it is larger than the sum of its proper divisors (797917).

21716771 is a wasteful number, since it uses less digits than its factorization.

21716771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3073.

The product of its digits is 4116, while the sum is 32.

The square root of 21716771 is about 4660.1256420831. The cubic root of 21716771 is about 278.9962829719.

The spelling of 21716771 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred seventy-one".