221012201609 has 2 divisors, whose sum is σ = 221012201610. Its totient is φ = 221012201608.

The previous prime is 221012201587. The next prime is 221012201617. The reversal of 221012201609 is 906102210122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158738496400 + 62273705209 = 398420^2 + 249547^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012201609 - 2¹² = 221012197513 is a prime.

It is not a weakly prime, because it can be changed into another prime (221012201689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110506100804 + 110506100805.

It is an arithmetic number, because the mean of its divisors is an integer number (110506100805).

Almost surely, 2^221012201609 is an apocalyptic number.

It is an amenable number.

221012201609 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012201609 is an equidigital number, since it uses as much as digits as its factorization.

221012201609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 221012201609 in words is "two hundred twenty-one billion, twelve million, two hundred one thousand, six hundred nine".