21029561646912 has 3024 divisors, whose sum is σ = 85194901471680. Its totient is φ = 4898566471680.

The previous prime is 21029561646887. The next prime is 21029561646923. The reversal of 21029561646912 is 21964616592012.

It is a happy number.

21029561646912 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 9 + 5 + 616 + 4 + 6 + 9 + 12 = 666.

It is a super-2 number, since 2×21029561646912² (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 (19) of ones.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 288076186908 + ... + 288076186980.

Almost surely, 2^{21029561646912} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21029561646912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42597450735840).

21029561646912 is an abundant number, since it is smaller than the sum of its proper divisors (64165339824768).

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

21029561646912 is a wasteful number, since it uses less digits than its factorization.

21029561646912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The spelling of 21029561646912 in words is "twenty-one trillion, twenty-nine billion, five hundred sixty-one million, six hundred forty-six thousand, nine hundred twelve".