1345404821 has 2 divisors, whose sum is σ = 1345404822. Its totient is φ = 1345404820.

The previous prime is 1345404811. The next prime is 1345404857. The reversal of 1345404821 is 1284045431.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1264584721 + 80820100 = 35561^2 + 8990^2 .

It is a cyclic number.

It is not a de Polignac number, because 1345404821 - 2³⁰ = 271662997 is a prime.

It is a super-2 number, since 2×1345404821² = 3620228264740084082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1345404811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 672702410 + 672702411.

It is an arithmetic number, because the mean of its divisors is an integer number (672702411).

Almost surely, 2^1345404821 is an apocalyptic number.

It is an amenable number.

1345404821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1345404821 is an equidigital number, since it uses as much as digits as its factorization.

1345404821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 1345404821 is about 36679.7603727178. The cubic root of 1345404821 is about 1103.9540400969.

The spelling of 1345404821 in words is "one billion, three hundred forty-five million, four hundred four thousand, eight hundred twenty-one".