21671435349 has 6 divisors (see below), whose sum is σ = 31303184406. Its totient is φ = 14447623560.

The previous prime is 21671435273. The next prime is 21671435363. The reversal of 21671435349 is 94353417612.

21671435349 is a `hidden beast` number, since 2 + 1 + 6 + 71 + 43 + 534 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21670784100 + 651249 = 147210^2 + 807^2 .

It is not a de Polignac number, because 21671435349 - 2¹² = 21671431253 is a prime.

It is a super-2 number, since 2×21671435349² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21671435749) 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, 1203968622 + ... + 1203968639.

It is an arithmetic number, because the mean of its divisors is an integer number (5217197401).

Almost surely, 2^21671435349 is an apocalyptic number.

It is an amenable number.

21671435349 is a deficient number, since it is larger than the sum of its proper divisors (9631749057).

21671435349 is a wasteful number, since it uses less digits than its factorization.

21671435349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2407937267 (or 2407937264 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The spelling of 21671435349 in words is "twenty-one billion, six hundred seventy-one million, four hundred thirty-five thousand, three hundred forty-nine".