7638691780 has 24 divisors (see below), whose sum is σ = 16343920152. Its totient is φ = 2997825792.

The previous prime is 7638691721. The next prime is 7638691799. The reversal of 7638691780 is 871968367.

It can be written as a sum of positive squares in 4 ways, for example, as 1803870784 + 5834820996 = 42472^2 + 76386^2 .

It is a super-2 number, since 2×7638691780² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3602097 + ... + 3604216.

It is an arithmetic number, because the mean of its divisors is an integer number (680996673).

Almost surely, 2^7638691780 is an apocalyptic number.

It is an amenable number.

7638691780 is an abundant number, since it is smaller than the sum of its proper divisors (8705228372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7638691780 is a wasteful number, since it uses less digits than its factorization.

7638691780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7206375 (or 7206373 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 55.

The square root of 7638691780 is about 87399.6097245291. The cubic root of 7638691780 is about 1969.4259778948.

The spelling of 7638691780 in words is "seven billion, six hundred thirty-eight million, six hundred ninety-one thousand, seven hundred eighty".