1346566721 has 4 divisors (see below), whose sum is σ = 1347889200. Its totient is φ = 1345244244.

The previous prime is 1346566667. The next prime is 1346566723. The reversal of 1346566721 is 1276656431.

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 1346566721 - 2²² = 1342372417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1346566723) 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, 659711 + ... + 661748.

It is an arithmetic number, because the mean of its divisors is an integer number (336972300).

Almost surely, 2^1346566721 is an apocalyptic number.

It is an amenable number.

1346566721 is a deficient number, since it is larger than the sum of its proper divisors (1322479).

1346566721 is a wasteful number, since it uses less digits than its factorization.

1346566721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322478.

The product of its digits is 181440, while the sum is 41.

The square root of 1346566721 is about 36695.5953896377. The cubic root of 1346566721 is about 1104.2717425241.

The spelling of 1346566721 in words is "one billion, three hundred forty-six million, five hundred sixty-six thousand, seven hundred twenty-one".