1351644985 has 4 divisors (see below), whose sum is σ = 1621973988. Its totient is φ = 1081315984.

The previous prime is 1351644967. The next prime is 1351644989. The reversal of 1351644985 is 5894461531.

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 336649104 + 1014995881 = 18348^2 + 31859^2 .

It is a cyclic number.

It is not a de Polignac number, because 1351644985 - 2⁵ = 1351644953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1351644989) 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, 135164494 + ... + 135164503.

It is an arithmetic number, because the mean of its divisors is an integer number (405493497).

Almost surely, 2^1351644985 is an apocalyptic number.

It is an amenable number.

1351644985 is a deficient number, since it is larger than the sum of its proper divisors (270329003).

1351644985 is an equidigital number, since it uses as much as digits as its factorization.

1351644985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270329002.

The product of its digits is 518400, while the sum is 46.

The square root of 1351644985 is about 36764.7247371716. The cubic root of 1351644985 is about 1105.6581693523.

The spelling of 1351644985 in words is "one billion, three hundred fifty-one million, six hundred forty-four thousand, nine hundred eighty-five".