221038397009 has 2 divisors, whose sum is σ = 221038397010. Its totient is φ = 221038397008.

The previous prime is 221038396961. The next prime is 221038397023. The reversal of 221038397009 is 900793830122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168079500625 + 52958896384 = 409975^2 + 230128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221038397009 is a prime.

It is not a weakly prime, because it can be changed into another prime (221038397059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110519198504 + 110519198505.

It is an arithmetic number, because the mean of its divisors is an integer number (110519198505).

Almost surely, 2^221038397009 is an apocalyptic number.

It is an amenable number.

221038397009 is a deficient number, since it is larger than the sum of its proper divisors (1).

221038397009 is an equidigital number, since it uses as much as digits as its factorization.

221038397009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 44.

The spelling of 221038397009 in words is "two hundred twenty-one billion, thirty-eight million, three hundred ninety-seven thousand, nine".