221801693 has 2 divisors, whose sum is σ = 221801694. Its totient is φ = 221801692.

The previous prime is 221801689. The next prime is 221801707. The reversal of 221801693 is 396108122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209149444 + 12652249 = 14462^2 + 3557^2 .

It is a cyclic number.

It is not a de Polignac number, because 221801693 - 2² = 221801689 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221801603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110900846 + 110900847.

It is an arithmetic number, because the mean of its divisors is an integer number (110900847).

Almost surely, 2^221801693 is an apocalyptic number.

It is an amenable number.

221801693 is a deficient number, since it is larger than the sum of its proper divisors (1).

221801693 is an equidigital number, since it uses as much as digits as its factorization.

221801693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 221801693 is about 14893.0081917657. The cubic root of 221801693 is about 605.3245468576.

The spelling of 221801693 in words is "two hundred twenty-one million, eight hundred one thousand, six hundred ninety-three".