7643987747 has 16 divisors (see below), whose sum is σ = 8483098464. Its totient is φ = 6829920000.

The previous prime is 7643987683. The next prime is 7643987749. The reversal of 7643987747 is 7477893467.

It is a cyclic number.

It is not a de Polignac number, because 7643987747 - 2⁶ = 7643987683 is a prime.

It is a super-2 number, since 2×7643987747² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7643987747.

It is not an unprimeable number, because it can be changed into a prime (7643987749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127097 + ... + 177317.

It is an arithmetic number, because the mean of its divisors is an integer number (530193654).

Almost surely, 2^7643987747 is an apocalyptic number.

7643987747 is a deficient number, since it is larger than the sum of its proper divisors (839110717).

7643987747 is a wasteful number, since it uses less digits than its factorization.

7643987747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50470.

The product of its digits is 49787136, while the sum is 62.

The square root of 7643987747 is about 87429.9019043256. The cubic root of 7643987747 is about 1969.8810124222.

The spelling of 7643987747 in words is "seven billion, six hundred forty-three million, nine hundred eighty-seven thousand, seven hundred forty-seven".