1321606761 has 4 divisors (see below), whose sum is σ = 1762142352. Its totient is φ = 881071172.

The previous prime is 1321606733. The next prime is 1321606789. The reversal of 1321606761 is 1676061231.

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 an interprime number because it is at equal distance from previous prime (1321606733) and next prime (1321606789).

It is a cyclic number.

It is not a de Polignac number, because 1321606761 - 2⁶ = 1321606697 is a prime.

It is a super-2 number, since 2×1321606761² = 3493288861441822242, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1321604761) 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, 220267791 + ... + 220267796.

It is an arithmetic number, because the mean of its divisors is an integer number (440535588).

Almost surely, 2^1321606761 is an apocalyptic number.

It is an amenable number.

1321606761 is a deficient number, since it is larger than the sum of its proper divisors (440535591).

1321606761 is an equidigital number, since it uses as much as digits as its factorization.

1321606761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440535590.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 1321606761 is about 36353.9098447471. The cubic root of 1321606761 is about 1097.4062195731.

Adding to 1321606761 its reverse (1676061231), we get a palindrome (2997667992).

The spelling of 1321606761 in words is "one billion, three hundred twenty-one million, six hundred six thousand, seven hundred sixty-one".