1561554223 has 2 divisors, whose sum is σ = 1561554224. Its totient is φ = 1561554222.

The previous prime is 1561554221. The next prime is 1561554301. The reversal of 1561554223 is 3224551651.

It is a weak prime.

It is an emirp because it is prime and its reverse (3224551651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1561554223 - 2¹ = 1561554221 is a prime.

Together with 1561554221, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561554221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780777111 + 780777112.

It is an arithmetic number, because the mean of its divisors is an integer number (780777112).

Almost surely, 2^1561554223 is an apocalyptic number.

1561554223 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561554223 is an equidigital number, since it uses as much as digits as its factorization.

1561554223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 34.

The square root of 1561554223 is about 39516.5057033134. The cubic root of 1561554223 is about 1160.1630327235.

The spelling of 1561554223 in words is "one billion, five hundred sixty-one million, five hundred fifty-four thousand, two hundred twenty-three".