1251261206 has 32 divisors (see below), whose sum is σ = 2109729888. Its totient is φ = 552764160.

The previous prime is 1251261191. The next prime is 1251261229. The reversal of 1251261206 is 6021621521.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45425 + ... + 67571.

It is an arithmetic number, because the mean of its divisors is an integer number (65929059).

Almost surely, 2^1251261206 is an apocalyptic number.

1251261206 is a deficient number, since it is larger than the sum of its proper divisors (858468682).

1251261206 is a wasteful number, since it uses less digits than its factorization.

1251261206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22256.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1251261206 is about 35373.1707088861. The cubic root of 1251261206 is about 1077.5795146988.

Adding to 1251261206 its reverse (6021621521), we get a palindrome (7272882727).

The spelling of 1251261206 in words is "one billion, two hundred fifty-one million, two hundred sixty-one thousand, two hundred six".