21905602011 has 20 divisors (see below), whose sum is σ = 32752304200. Its totient is φ = 14590738656.

The previous prime is 21905602007. The next prime is 21905602027. The reversal of 21905602011 is 11020650912.

21905602011 is a `hidden beast` number, since 2 + 1 + 90 + 560 + 2 + 0 + 11 = 666.

It is not a de Polignac number, because 21905602011 - 2² = 21905602007 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21905602031) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 28321 + ... + 211218.

It is an arithmetic number, because the mean of its divisors is an integer number (1637615210).

Almost surely, 2^21905602011 is an apocalyptic number.

21905602011 is a deficient number, since it is larger than the sum of its proper divisors (10846702189).

21905602011 is a wasteful number, since it uses less digits than its factorization.

21905602011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240680 (or 240671 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The spelling of 21905602011 in words is "twenty-one billion, nine hundred five million, six hundred two thousand, eleven".