1357128749 has 4 divisors (see below), whose sum is σ = 1357973820. Its totient is φ = 1356283680.

The previous prime is 1357128743. The next prime is 1357128763. The reversal of 1357128749 is 9478217531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9478217531 = 15161 ⋅625171.

It can be written as a sum of positive squares in 2 ways, for example, as 1237773124 + 119355625 = 35182^2 + 10925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1357128749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1357128743) 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, 420122 + ... + 423339.

It is an arithmetic number, because the mean of its divisors is an integer number (339493455).

Almost surely, 2^1357128749 is an apocalyptic number.

It is an amenable number.

1357128749 is a deficient number, since it is larger than the sum of its proper divisors (845071).

1357128749 is an equidigital number, since it uses as much as digits as its factorization.

1357128749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845070.

The product of its digits is 423360, while the sum is 47.

The square root of 1357128749 is about 36839.2283985428. The cubic root of 1357128749 is about 1107.1514084128.

The spelling of 1357128749 in words is "one billion, three hundred fifty-seven million, one hundred twenty-eight thousand, seven hundred forty-nine".