1356793721 has 4 divisors (see below), whose sum is σ = 1362073332. Its totient is φ = 1351514112.

The previous prime is 1356793661. The next prime is 1356793723. The reversal of 1356793721 is 1273976531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1058851600 + 297942121 = 32540^2 + 17261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1356793721 - 2³⁰ = 283051897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1356793723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2639420 + ... + 2639933.

It is an arithmetic number, because the mean of its divisors is an integer number (340518333).

Almost surely, 2^1356793721 is an apocalyptic number.

It is an amenable number.

1356793721 is a deficient number, since it is larger than the sum of its proper divisors (5279611).

1356793721 is an equidigital number, since it uses as much as digits as its factorization.

1356793721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5279610.

The product of its digits is 238140, while the sum is 44.

The square root of 1356793721 is about 36834.6809542312. The cubic root of 1356793721 is about 1107.0602951588.

The spelling of 1356793721 in words is "one billion, three hundred fifty-six million, seven hundred ninety-three thousand, seven hundred twenty-one".