21655210442 has 16 divisors (see below), whose sum is σ = 34219164960. Its totient is φ = 10249713072.

The previous prime is 21655210433. The next prime is 21655210477. The reversal of 21655210442 is 24401255612.

It is a junction number, because it is equal to n+sod(n) for n = 21655210399 and 21655210408.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173333 + ... + 270840.

It is an arithmetic number, because the mean of its divisors is an integer number (2138697810).

Almost surely, 2^21655210442 is an apocalyptic number.

21655210442 is a deficient number, since it is larger than the sum of its proper divisors (12563954518).

21655210442 is a wasteful number, since it uses less digits than its factorization.

21655210442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445477.

The product of its (nonzero) digits is 19200, while the sum is 32.

The spelling of 21655210442 in words is "twenty-one billion, six hundred fifty-five million, two hundred ten thousand, four hundred forty-two".