21569138051728 has 10 divisors (see below), whose sum is σ = 41790204975254. Its totient is φ = 10784569025856.

The previous prime is 21569138051711. The next prime is 21569138051731. The reversal of 21569138051728 is 82715083196512.

It can be written as a sum of positive squares in only one way, i.e., 15468079970704 + 6101058081024 = 3932948^2 + 2470032^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 674035564101 + ... + 674035564132.

Almost surely, 2^{21569138051728} is an apocalyptic number.

It is an amenable number.

21569138051728 is a deficient number, since it is larger than the sum of its proper divisors (20221066923526).

21569138051728 is a wasteful number, since it uses less digits than its factorization.

21569138051728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348071128241 (or 1348071128235 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 58.

The spelling of 21569138051728 in words is "twenty-one trillion, five hundred sixty-nine billion, one hundred thirty-eight million, fifty-one thousand, seven hundred twenty-eight".