1213327765 has 16 divisors (see below), whose sum is σ = 1568852208. Its totient is φ = 895504896.

The previous prime is 1213327751. The next prime is 1213327769. The reversal of 1213327765 is 5677233121.

It can be written as a sum of positive squares in 8 ways, for example, as 432348849 + 780978916 = 20793^2 + 27946^2 .

It is not a de Polignac number, because 1213327765 - 2⁹ = 1213327253 is a prime.

It is a super-3 number, since 3×1213327765³ (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 (1213327769) 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, 150579 + ... + 158431.

It is an arithmetic number, because the mean of its divisors is an integer number (98053263).

Almost surely, 2^1213327765 is an apocalyptic number.

It is an amenable number.

1213327765 is a deficient number, since it is larger than the sum of its proper divisors (355524443).

1213327765 is a wasteful number, since it uses less digits than its factorization.

1213327765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10248.

The product of its digits is 52920, while the sum is 37.

The square root of 1213327765 is about 34832.8546777321. The cubic root of 1213327765 is about 1066.5782224302.

The spelling of 1213327765 in words is "one billion, two hundred thirteen million, three hundred twenty-seven thousand, seven hundred sixty-five".