21029735890944 has 1176 divisors, whose sum is σ = 71626229471664. Its totient is φ = 6115295232000.

The previous prime is 21029735890939. The next prime is 21029735890957. The reversal of 21029735890944 is 44909853792012.

21029735890944 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 9 + 7 + 3 + 589 + 0 + 9 + 44 = 666.

It is a super-2 number, since 2×21029735890944² (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 (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 344749768674 + ... + 344749768734.

It is an arithmetic number, because the mean of its divisors is an integer number (60906657714).

Almost surely, 2^{21029735890944} is an apocalyptic number.

21029735890944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21029735890944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35813114735832).

21029735890944 is an abundant number, since it is smaller than the sum of its proper divisors (50596493580720).

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

21029735890944 is an frugal number, since it uses more digits than its factorization.

21029735890944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 39191040, while the sum is 63.

The spelling of 21029735890944 in words is "twenty-one trillion, twenty-nine billion, seven hundred thirty-five million, eight hundred ninety thousand, nine hundred forty-four".