1261506053 has 4 divisors (see below), whose sum is σ = 1285308108. Its totient is φ = 1237704000.

The previous prime is 1261506041. The next prime is 1261506089. The reversal of 1261506053 is 3506051621.

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 715723009 + 545783044 = 26753^2 + 23362^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261506053 - 2⁶ = 1261505989 is a prime.

It is a super-3 number, since 3×1261506053³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261506853) 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, 11900948 + ... + 11901053.

It is an arithmetic number, because the mean of its divisors is an integer number (321327027).

Almost surely, 2^1261506053 is an apocalyptic number.

It is an amenable number.

1261506053 is a deficient number, since it is larger than the sum of its proper divisors (23802055).

1261506053 is an equidigital number, since it uses as much as digits as its factorization.

1261506053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23802054.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 1261506053 is about 35517.6864815264. The cubic root of 1261506053 is about 1080.5124605596.

Adding to 1261506053 its reverse (3506051621), we get a palindrome (4767557674).

The spelling of 1261506053 in words is "one billion, two hundred sixty-one million, five hundred six thousand, fifty-three".