1555726161 has 24 divisors (see below), whose sum is σ = 2341659712. Its totient is φ = 917373600.

The previous prime is 1555726121. The next prime is 1555726169. The reversal of 1555726161 is 1616275551.

It is a happy number.

It is not a de Polignac number, because 1555726161 - 2¹⁰ = 1555725137 is a prime.

It is a super-3 number, since 3×1555726161³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1555726169) 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 23 ways as a sum of consecutive naturals, for example, 44485 + ... + 71346.

Almost surely, 2^1555726161 is an apocalyptic number.

1555726161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1555726161 is a deficient number, since it is larger than the sum of its proper divisors (785933551).

1555726161 is a wasteful number, since it uses less digits than its factorization.

1555726161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115893 (or 115882 counting only the distinct ones).

The product of its digits is 63000, while the sum is 39.

The square root of 1555726161 is about 39442.6946467911. The cubic root of 1555726161 is about 1158.7179059663.

The spelling of 1555726161 in words is "one billion, five hundred fifty-five million, seven hundred twenty-six thousand, one hundred sixty-one".