2155431101 has 4 divisors (see below), whose sum is σ = 2159415804. Its totient is φ = 2151446400.

The previous prime is 2155431077. The next prime is 2155431121. The reversal of 2155431101 is 1011345512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 391011076 + 1764420025 = 19774^2 + 42005^2 .

It is a cyclic number.

It is not a de Polignac number, because 2155431101 - 2¹⁰ = 2155430077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155431121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1991540 + ... + 1992621.

It is an arithmetic number, because the mean of its divisors is an integer number (539853951).

Almost surely, 2^2155431101 is an apocalyptic number.

It is an amenable number.

2155431101 is a deficient number, since it is larger than the sum of its proper divisors (3984703).

2155431101 is an equidigital number, since it uses as much as digits as its factorization.

2155431101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3984702.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 2155431101 is about 46426.6206071474. The cubic root of 2155431101 is about 1291.7487452210.

Adding to 2155431101 its reverse (1011345512), we get a palindrome (3166776613).

The spelling of 2155431101 in words is "two billion, one hundred fifty-five million, four hundred thirty-one thousand, one hundred one".