21671271634 has 4 divisors (see below), whose sum is σ = 32506907454. Its totient is φ = 10835635816.

The previous prime is 21671271619. The next prime is 21671271647. The reversal of 21671271634 is 43617217612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21639292609 + 31979025 = 147103^2 + 5655^2 .

It is a super-3 number, since 3×21671271634³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5417817907 + ... + 5417817910.

Almost surely, 2^21671271634 is an apocalyptic number.

21671271634 is a deficient number, since it is larger than the sum of its proper divisors (10835635820).

21671271634 is a wasteful number, since it uses less digits than its factorization.

21671271634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10835635819.

The product of its digits is 84672, while the sum is 40.

The spelling of 21671271634 in words is "twenty-one billion, six hundred seventy-one million, two hundred seventy-one thousand, six hundred thirty-four".