21782610871 has 6 divisors (see below), whose sum is σ = 25338955560. Its totient is φ = 18670809276.

The previous prime is 21782610869. The next prime is 21782610887. The reversal of 21782610871 is 17801628712.

It is not a de Polignac number, because 21782610871 - 2¹ = 21782610869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21782611871) 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, 222271491 + ... + 222271588.

It is an arithmetic number, because the mean of its divisors is an integer number (4223159260).

Almost surely, 2^21782610871 is an apocalyptic number.

21782610871 is a deficient number, since it is larger than the sum of its proper divisors (3556344689).

21782610871 is an equidigital number, since it uses as much as digits as its factorization.

21782610871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444543093 (or 444543086 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 43.

The spelling of 21782610871 in words is "twenty-one billion, seven hundred eighty-two million, six hundred ten thousand, eight hundred seventy-one".