221656427663531 has 8 divisors (see below), whose sum is σ = 253321754550240. Its totient is φ = 189991131510528.

The previous prime is 221656427663501. The next prime is 221656427663647. The reversal of 221656427663531 is 135366724656122.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221656427663531 is a prime.

It is a super-2 number, since 2×221656427663531² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221656427663501) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 10705145 + ... + 23620181.

It is an arithmetic number, because the mean of its divisors is an integer number (31665219318780).

Almost surely, 2^{221656427663531} is an apocalyptic number.

221656427663531 is a deficient number, since it is larger than the sum of its proper divisors (31665326886709).

221656427663531 is a wasteful number, since it uses less digits than its factorization.

221656427663531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15366853.

The product of its digits is 65318400, while the sum is 59.

The spelling of 221656427663531 in words is "two hundred twenty-one trillion, six hundred fifty-six billion, four hundred twenty-seven million, six hundred sixty-three thousand, five hundred thirty-one".