221873735651 has 2 divisors, whose sum is σ = 221873735652. Its totient is φ = 221873735650.

The previous prime is 221873735623. The next prime is 221873735701. The reversal of 221873735651 is 156537378122.

It is an a-pointer prime, because the next prime (221873735701) can be obtained adding 221873735651 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221873735651 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221873735651.

It is not a weakly prime, because it can be changed into another prime (221873735851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110936867825 + 110936867826.

It is an arithmetic number, because the mean of its divisors is an integer number (110936867826).

Almost surely, 2^221873735651 is an apocalyptic number.

221873735651 is a deficient number, since it is larger than the sum of its proper divisors (1).

221873735651 is an equidigital number, since it uses as much as digits as its factorization.

221873735651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2116800, while the sum is 50.

The spelling of 221873735651 in words is "two hundred twenty-one billion, eight hundred seventy-three million, seven hundred thirty-five thousand, six hundred fifty-one".