1205125149 has 4 divisors (see below), whose sum is σ = 1606833536. Its totient is φ = 803416764.

The previous prime is 1205125147. The next prime is 1205125151. The reversal of 1205125149 is 9415215021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9415215021 = 3 ⋅3138405007.

It is an interprime number because it is at equal distance from previous prime (1205125147) and next prime (1205125151).

It is not a de Polignac number, because 1205125149 - 2¹ = 1205125147 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 (1205125147) 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, 200854189 + ... + 200854194.

It is an arithmetic number, because the mean of its divisors is an integer number (401708384).

Almost surely, 2^1205125149 is an apocalyptic number.

It is an amenable number.

1205125149 is a deficient number, since it is larger than the sum of its proper divisors (401708387).

1205125149 is an equidigital number, since it uses as much as digits as its factorization.

1205125149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401708386.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 1205125149 is about 34714.9124872871. The cubic root of 1205125149 is about 1064.1692770252.

The spelling of 1205125149 in words is "one billion, two hundred five million, one hundred twenty-five thousand, one hundred forty-nine".