21557710116281 has 8 divisors (see below), whose sum is σ = 22672990312704. Its totient is φ = 20468671806960.

The previous prime is 21557710116263. The next prime is 21557710116323. The reversal of 21557710116281 is 18261101775512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21557710116281 - 2¹⁰ = 21557710115257 is a prime.

It is a super-2 number, since 2×21557710116281² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21557710116881) 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, 6560470091 + ... + 6560473376.

It is an arithmetic number, because the mean of its divisors is an integer number (2834123789088).

Almost surely, 2^{21557710116281} is an apocalyptic number.

It is an amenable number.

21557710116281 is a deficient number, since it is larger than the sum of its proper divisors (1115280196423).

21557710116281 is a wasteful number, since it uses less digits than its factorization.

21557710116281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13120943551.

The product of its (nonzero) digits is 235200, while the sum is 47.

The spelling of 21557710116281 in words is "twenty-one trillion, five hundred fifty-seven billion, seven hundred ten million, one hundred sixteen thousand, two hundred eighty-one".