21235716771 has 8 divisors (see below), whose sum is σ = 28336024320. Its totient is φ = 14146276872.

The previous prime is 21235716737. The next prime is 21235716793. The reversal of 21235716771 is 17761753212.

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

It is not a de Polignac number, because 21235716771 - 2¹⁷ = 21235585699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21235736771) 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, 2712351 + ... + 2720168.

It is an arithmetic number, because the mean of its divisors is an integer number (3542003040).

Almost surely, 2^21235716771 is an apocalyptic number.

21235716771 is a deficient number, since it is larger than the sum of its proper divisors (7100307549).

21235716771 is a wasteful number, since it uses less digits than its factorization.

21235716771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5433825.

The product of its digits is 123480, while the sum is 42.

The spelling of 21235716771 in words is "twenty-one billion, two hundred thirty-five million, seven hundred sixteen thousand, seven hundred seventy-one".