21261366053044 has 24 divisors (see below), whose sum is σ = 40069693450080. Its totient is φ = 9812890205664.

The previous prime is 21261366052999. The next prime is 21261366053047. The reversal of 21261366053044 is 44035066316212.

It is a happy number.

It is a super-3 number, since 3×21261366053044³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261366053047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11145027 + ... + 12912565.

It is an arithmetic number, because the mean of its divisors is an integer number (1669570560420).

Almost surely, 2^{21261366053044} is an apocalyptic number.

It is an amenable number.

21261366053044 is a deficient number, since it is larger than the sum of its proper divisors (18808327397036).

21261366053044 is a wasteful number, since it uses less digits than its factorization.

21261366053044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1998879 (or 1998877 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 43.

The spelling of 21261366053044 in words is "twenty-one trillion, two hundred sixty-one billion, three hundred sixty-six million, fifty-three thousand, forty-four".