1361555431 has 4 divisors (see below), whose sum is σ = 1363214664. Its totient is φ = 1359896200.

The previous prime is 1361555411. The next prime is 1361555467. The reversal of 1361555431 is 1345551631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1345551631 = 313 ⋅4298887.

It is a cyclic number.

It is not a de Polignac number, because 1361555431 - 2¹⁹ = 1361031143 is a prime.

It is a super-2 number, since 2×1361555431² = 3707666383371191522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1361555401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 828385 + ... + 830026.

It is an arithmetic number, because the mean of its divisors is an integer number (340803666).

Almost surely, 2^1361555431 is an apocalyptic number.

1361555431 is a deficient number, since it is larger than the sum of its proper divisors (1659233).

1361555431 is an equidigital number, since it uses as much as digits as its factorization.

1361555431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659232.

The product of its digits is 27000, while the sum is 34.

The square root of 1361555431 is about 36899.2605752473. The cubic root of 1361555431 is about 1108.3538706328.

The spelling of 1361555431 in words is "one billion, three hundred sixty-one million, five hundred fifty-five thousand, four hundred thirty-one".