21655044203064 has 64 divisors (see below), whose sum is σ = 57323518560000. Its totient is φ = 6793580219904.

The previous prime is 21655044203041. The next prime is 21655044203087. The reversal of 21655044203064 is 46030244055612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21655044203041) and next prime (21655044203087).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17461437 + ... + 18660435.

It is an arithmetic number, because the mean of its divisors is an integer number (895679977500).

Almost surely, 2^{21655044203064} is an apocalyptic number.

21655044203064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21655044203064 is an abundant number, since it is smaller than the sum of its proper divisors (35668474356936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21655044203064 is a wasteful number, since it uses less digits than its factorization.

21655044203064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243292 (or 1243288 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 42.

Adding to 21655044203064 its reverse (46030244055612), we get a palindrome (67685288258676).

The spelling of 21655044203064 in words is "twenty-one trillion, six hundred fifty-five billion, forty-four million, two hundred three thousand, sixty-four".