742778665 has 4 divisors (see below), whose sum is σ = 891334404. Its totient is φ = 594222928.

The previous prime is 742778657. The next prime is 742778669. The reversal of 742778665 is 566877247.

742778665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 179238544 + 563540121 = 13388^2 + 23739^2 .

It is a cyclic number.

It is not a de Polignac number, because 742778665 - 2³ = 742778657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (742778669) 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, 74277862 + ... + 74277871.

It is an arithmetic number, because the mean of its divisors is an integer number (222833601).

Almost surely, 2^742778665 is an apocalyptic number.

It is an amenable number.

742778665 is a deficient number, since it is larger than the sum of its proper divisors (148555739).

742778665 is a wasteful number, since it uses less digits than its factorization.

742778665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148555738.

The product of its digits is 3951360, while the sum is 52.

The square root of 742778665 is about 27253.9660416608. The cubic root of 742778665 is about 905.6348790351.

The spelling of 742778665 in words is "seven hundred forty-two million, seven hundred seventy-eight thousand, six hundred sixty-five".