21158646111 has 12 divisors (see below), whose sum is σ = 31063514040. Its totient is φ = 13874521680.

The previous prime is 21158646109. The next prime is 21158646121. The reversal of 21158646111 is 11164685112.

21158646111 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 8 + 646 + 1 + 1 + 1 = 666.

It is not a de Polignac number, because 21158646111 - 2¹ = 21158646109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158646121) 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, 19269621 + ... + 19270718.

It is an arithmetic number, because the mean of its divisors is an integer number (2588626170).

Almost surely, 2^21158646111 is an apocalyptic number.

21158646111 is a deficient number, since it is larger than the sum of its proper divisors (9904867929).

21158646111 is a wasteful number, since it uses less digits than its factorization.

21158646111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38540406 (or 38540403 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The spelling of 21158646111 in words is "twenty-one billion, one hundred fifty-eight million, six hundred forty-six thousand, one hundred eleven".