1555431223 has 2 divisors, whose sum is σ = 1555431224. Its totient is φ = 1555431222.

The previous prime is 1555431193. The next prime is 1555431233. The reversal of 1555431223 is 3221345551.

It is a strong prime.

It is an emirp because it is prime and its reverse (3221345551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1555431223 - 2²⁹ = 1018560311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1555431233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777715611 + 777715612.

It is an arithmetic number, because the mean of its divisors is an integer number (777715612).

Almost surely, 2^1555431223 is an apocalyptic number.

1555431223 is a deficient number, since it is larger than the sum of its proper divisors (1).

1555431223 is an equidigital number, since it uses as much as digits as its factorization.

1555431223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18000, while the sum is 31.

The square root of 1555431223 is about 39438.9556530089. The cubic root of 1555431223 is about 1158.6446772390.

Adding to 1555431223 its reverse (3221345551), we get a palindrome (4776776774).

The spelling of 1555431223 in words is "one billion, five hundred fifty-five million, four hundred thirty-one thousand, two hundred twenty-three".