21655416043366 has 16 divisors (see below), whose sum is σ = 38403693476640. Its totient is φ = 8960861810880.

The previous prime is 21655416043321. The next prime is 21655416043423. The reversal of 21655416043366 is 66334061455612.

It is a super-2 number, since 2×21655416043366² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26669231175 + ... + 26669231986.

It is an arithmetic number, because the mean of its divisors is an integer number (2400230842290).

Almost surely, 2^{21655416043366} is an apocalyptic number.

21655416043366 is a deficient number, since it is larger than the sum of its proper divisors (16748277433274).

21655416043366 is a wasteful number, since it uses less digits than its factorization.

21655416043366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53338463199.

The product of its (nonzero) digits is 9331200, while the sum is 52.

Adding to 21655416043366 its reverse (66334061455612), we get a palindrome (87989477498978).

The spelling of 21655416043366 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred sixteen million, forty-three thousand, three hundred sixty-six".