7542021665 has 8 divisors (see below), whose sum is σ = 9051117288. Its totient is φ = 6033156480.

The previous prime is 7542021653. The next prime is 7542021667. The reversal of 7542021665 is 5661202457.

It can be written as a sum of positive squares in 4 ways, for example, as 3070157281 + 4471864384 = 55409^2 + 66872^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7542021665 - 2⁴ = 7542021649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7542021667) 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 7 ways as a sum of consecutive naturals, for example, 25229 + ... + 125381.

It is an arithmetic number, because the mean of its divisors is an integer number (1131389661).

Almost surely, 2^7542021665 is an apocalyptic number.

It is an amenable number.

7542021665 is a deficient number, since it is larger than the sum of its proper divisors (1509095623).

7542021665 is a wasteful number, since it uses less digits than its factorization.

7542021665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115219.

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 7542021665 is about 86844.8136908589. The cubic root of 7542021665 is about 1961.0827754064.

The spelling of 7542021665 in words is "seven billion, five hundred forty-two million, twenty-one thousand, six hundred sixty-five".