1205211601 has 4 divisors (see below), whose sum is σ = 1314776304. Its totient is φ = 1095646900.

The previous prime is 1205211589. The next prime is 1205211643. The reversal of 1205211601 is 1061125021.

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.

It is a cyclic number.

It is not a de Polignac number, because 1205211601 - 2⁷ = 1205211473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1205211671) 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, 54782335 + ... + 54782356.

It is an arithmetic number, because the mean of its divisors is an integer number (328694076).

Almost surely, 2^1205211601 is an apocalyptic number.

1205211601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1205211601 is a deficient number, since it is larger than the sum of its proper divisors (109564703).

1205211601 is a wasteful number, since it uses less digits than its factorization.

1205211601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109564702.

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 1205211601 is about 34716.1576358905. The cubic root of 1205211601 is about 1064.1947231687.

Adding to 1205211601 its reverse (1061125021), we get a palindrome (2266336622).

It can be divided in two parts, 12052 and 11601, that added together give a triangular number (23653 = T₂₁₇).

The spelling of 1205211601 in words is "one billion, two hundred five million, two hundred eleven thousand, six hundred one".