1345533721 has 4 divisors (see below), whose sum is σ = 1537752832. Its totient is φ = 1153314612.

The previous prime is 1345533691. The next prime is 1345533743. The reversal of 1345533721 is 1273355431.

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 1345533721 - 2⁹ = 1345533209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1345533751) 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, 96109545 + ... + 96109558.

It is an arithmetic number, because the mean of its divisors is an integer number (384438208).

Almost surely, 2^1345533721 is an apocalyptic number.

It is an amenable number.

1345533721 is a deficient number, since it is larger than the sum of its proper divisors (192219111).

1345533721 is an equidigital number, since it uses as much as digits as its factorization.

1345533721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192219110.

The product of its digits is 37800, while the sum is 34.

The square root of 1345533721 is about 36681.5174304444. The cubic root of 1345533721 is about 1103.9892946981.

The spelling of 1345533721 in words is "one billion, three hundred forty-five million, five hundred thirty-three thousand, seven hundred twenty-one".