1357107721 has 4 divisors (see below), whose sum is σ = 1357242372. Its totient is φ = 1356973072.

The previous prime is 1357107707. The next prime is 1357107743. The reversal of 1357107721 is 1277017531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1277017531 = 19 ⋅67211449.

It can be written as a sum of positive squares in 2 ways, for example, as 914215696 + 442892025 = 30236^2 + 21045^2 .

It is a cyclic number.

It is not a de Polignac number, because 1357107721 - 2⁷ = 1357107593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1357107701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50866 + ... + 72811.

It is an arithmetic number, because the mean of its divisors is an integer number (339310593).

Almost surely, 2^1357107721 is an apocalyptic number.

It is an amenable number.

1357107721 is a deficient number, since it is larger than the sum of its proper divisors (134651).

1357107721 is a wasteful number, since it uses less digits than its factorization.

1357107721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134650.

The product of its (nonzero) digits is 10290, while the sum is 34.

The square root of 1357107721 is about 36838.9429951512. The cubic root of 1357107721 is about 1107.1456901393.

The spelling of 1357107721 in words is "one billion, three hundred fifty-seven million, one hundred seven thousand, seven hundred twenty-one".