1206981261 has 18 divisors (see below), whose sum is σ = 1751439690. Its totient is φ = 800968320.

The previous prime is 1206981253. The next prime is 1206981271. The reversal of 1206981261 is 1621896021.

It can be written as a sum of positive squares in 3 ways, for example, as 669205161 + 537776100 = 25869^2 + 23190^2 .

It is not a de Polignac number, because 1206981261 - 2³ = 1206981253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1206981271) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 521575 + ... + 523883.

It is an arithmetic number, because the mean of its divisors is an integer number (97302205).

Almost surely, 2^1206981261 is an apocalyptic number.

It is an amenable number.

1206981261 is a deficient number, since it is larger than the sum of its proper divisors (544458429).

1206981261 is an equidigital number, since it uses as much as digits as its factorization.

1206981261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2797 (or 2553 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1206981261 is about 34741.6358423146. The cubic root of 1206981261 is about 1064.7153348817.

The spelling of 1206981261 in words is "one billion, two hundred six million, nine hundred eighty-one thousand, two hundred sixty-one".