1251406261 has 16 divisors (see below), whose sum is σ = 1529314560. Its totient is φ = 999532800.

The previous prime is 1251406259. The next prime is 1251406279. The reversal of 1251406261 is 1626041521.

It is not a de Polignac number, because 1251406261 - 2¹ = 1251406259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251106261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40041 + ... + 64078.

It is an arithmetic number, because the mean of its divisors is an integer number (95582160).

Almost surely, 2^1251406261 is an apocalyptic number.

It is an amenable number.

1251406261 is a deficient number, since it is larger than the sum of its proper divisors (277908299).

1251406261 is a wasteful number, since it uses less digits than its factorization.

1251406261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104244.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1251406261 is about 35375.2210028432. The cubic root of 1251406261 is about 1077.6211532887.

Adding to 1251406261 its reverse (1626041521), we get a palindrome (2877447782).

The spelling of 1251406261 in words is "one billion, two hundred fifty-one million, four hundred six thousand, two hundred sixty-one".