7639440121 has 4 divisors (see below), whose sum is σ = 7715078244. Its totient is φ = 7563802000.

The previous prime is 7639440091. The next prime is 7639440131. The reversal of 7639440121 is 1210449367.

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 6651218025 + 988222096 = 81555^2 + 31436^2 .

It is a cyclic number.

It is not a de Polignac number, because 7639440121 - 2⁷ = 7639439993 is a prime.

It is a super-3 number, since 3×7639440121³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7639440131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37818910 + ... + 37819111.

It is an arithmetic number, because the mean of its divisors is an integer number (1928769561).

Almost surely, 2^7639440121 is an apocalyptic number.

It is an amenable number.

7639440121 is a deficient number, since it is larger than the sum of its proper divisors (75638123).

7639440121 is a wasteful number, since it uses less digits than its factorization.

7639440121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75638122.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 7639440121 is about 87403.8907658006. The cubic root of 7639440121 is about 1969.4902888232.

Adding to 7639440121 its reverse (1210449367), we get a palindrome (8849889488).

The spelling of 7639440121 in words is "seven billion, six hundred thirty-nine million, four hundred forty thousand, one hundred twenty-one".