21577281851027 has 16 divisors (see below), whose sum is σ = 24973172490240. Its totient is φ = 18259770533472.

The previous prime is 21577281850981. The next prime is 21577281851039. The reversal of 21577281851027 is 72015818277512.

It is a cyclic number.

It is not a de Polignac number, because 21577281851027 - 2⁸ = 21577281850771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21577281851227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9971918 + ... + 11941260.

It is an arithmetic number, because the mean of its divisors is an integer number (1560823280640).

Almost surely, 2^{21577281851027} is an apocalyptic number.

21577281851027 is a deficient number, since it is larger than the sum of its proper divisors (3395890639213).

21577281851027 is a wasteful number, since it uses less digits than its factorization.

21577281851027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1989242.

The product of its (nonzero) digits is 4390400, while the sum is 56.

The spelling of 21577281851027 in words is "twenty-one trillion, five hundred seventy-seven billion, two hundred eighty-one million, eight hundred fifty-one thousand, twenty-seven".