1261304011 has 16 divisors (see below), whose sum is σ = 1398728448. Its totient is φ = 1127728800.

The previous prime is 1261303987. The next prime is 1261304021. The reversal of 1261304011 is 1104031621.

It is not a de Polignac number, because 1261304011 - 2⁹ = 1261303499 is a prime.

It is a super-5 number, since 5×1261304011⁵ (a number of 47 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261304011.

It is not an unprimeable number, because it can be changed into a prime (1261304021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 723601 + ... + 725341.

It is an arithmetic number, because the mean of its divisors is an integer number (87420528).

Almost surely, 2^1261304011 is an apocalyptic number.

1261304011 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1261304011 is a deficient number, since it is larger than the sum of its proper divisors (137424437).

1261304011 is a wasteful number, since it uses less digits than its factorization.

1261304011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2802.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1261304011 is about 35514.8421226957. The cubic root of 1261304011 is about 1080.4547727523.

Adding to 1261304011 its reverse (1104031621), we get a palindrome (2365335632).

The spelling of 1261304011 in words is "one billion, two hundred sixty-one million, three hundred four thousand, eleven".