1561217227 has 2 divisors, whose sum is σ = 1561217228. Its totient is φ = 1561217226.

The previous prime is 1561217149. The next prime is 1561217249. The reversal of 1561217227 is 7227121651.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561217227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1561217192 and 1561217201.

It is not a weakly prime, because it can be changed into another prime (1561287227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780608613 + 780608614.

It is an arithmetic number, because the mean of its divisors is an integer number (780608614).

Almost surely, 2^1561217227 is an apocalyptic number.

1561217227 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561217227 is an equidigital number, since it uses as much as digits as its factorization.

1561217227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11760, while the sum is 34.

The square root of 1561217227 is about 39512.2414828620. The cubic root of 1561217227 is about 1160.0795692050.

Adding to 1561217227 its reverse (7227121651), we get a palindrome (8788338878).

The spelling of 1561217227 in words is "one billion, five hundred sixty-one million, two hundred seventeen thousand, two hundred twenty-seven".