21381167349 has 12 divisors (see below), whose sum is σ = 32027757216. Its totient is φ = 14254111404.

The previous prime is 21381167329. The next prime is 21381167351. The reversal of 21381167349 is 94376118312.

21381167349 is a `hidden beast` number, since 213 + 81 + 16 + 7 + 349 = 666.

It is not a de Polignac number, because 21381167349 - 2⁹ = 21381166837 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21381167329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43993929 + ... + 43994414.

It is an arithmetic number, because the mean of its divisors is an integer number (2668979768).

Almost surely, 2^21381167349 is an apocalyptic number.

It is an amenable number.

21381167349 is a deficient number, since it is larger than the sum of its proper divisors (10646589867).

21381167349 is an frugal number, since it uses more digits than its factorization.

21381167349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87988358 (or 87988346 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The spelling of 21381167349 in words is "twenty-one billion, three hundred eighty-one million, one hundred sixty-seven thousand, three hundred forty-nine".