1965291261 has 4 divisors (see below), whose sum is σ = 2620388352. Its totient is φ = 1310194172.

The previous prime is 1965291259. The next prime is 1965291287. The reversal of 1965291261 is 1621925691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1965291261 - 2¹ = 1965291259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1965291661) 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, 327548541 + ... + 327548546.

It is an arithmetic number, because the mean of its divisors is an integer number (655097088).

Almost surely, 2^1965291261 is an apocalyptic number.

It is an amenable number.

1965291261 is a deficient number, since it is larger than the sum of its proper divisors (655097091).

1965291261 is an equidigital number, since it uses as much as digits as its factorization.

1965291261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655097090.

The product of its digits is 58320, while the sum is 42.

The square root of 1965291261 is about 44331.6056668377. The cubic root of 1965291261 is about 1252.5900984186.

The spelling of 1965291261 in words is "one billion, nine hundred sixty-five million, two hundred ninety-one thousand, two hundred sixty-one".