221657761161643 has 16 divisors (see below), whose sum is σ = 228861823905792. Its totient is φ = 214457067504000.

The previous prime is 221657761161583. The next prime is 221657761161659. The reversal of 221657761161643 is 346161167756122.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221657761161643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221657761161143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2917164030 + ... + 2917240012.

It is an arithmetic number, because the mean of its divisors is an integer number (14303863994112).

Almost surely, 2^{221657761161643} is an apocalyptic number.

221657761161643 is a deficient number, since it is larger than the sum of its proper divisors (7204062744149).

221657761161643 is a wasteful number, since it uses less digits than its factorization.

221657761161643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96906.

The product of its digits is 15240960, while the sum is 58.

The spelling of 221657761161643 in words is "two hundred twenty-one trillion, six hundred fifty-seven billion, seven hundred sixty-one million, one hundred sixty-one thousand, six hundred forty-three".