21749194066 has 16 divisors (see below), whose sum is σ = 33209763840. Its totient is φ = 10680714720.

The previous prime is 21749194043. The next prime is 21749194081. The reversal of 21749194066 is 66049194712.

It is a super-2 number, since 2×21749194066² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 330171 + ... + 390526.

It is an arithmetic number, because the mean of its divisors is an integer number (2075610240).

Almost surely, 2^21749194066 is an apocalyptic number.

21749194066 is a deficient number, since it is larger than the sum of its proper divisors (11460569774).

21749194066 is a wasteful number, since it uses less digits than its factorization.

21749194066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720969.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 21749194066 in words is "twenty-one billion, seven hundred forty-nine million, one hundred ninety-four thousand, sixty-six".