7656377721 has 16 divisors (see below), whose sum is σ = 10441643904. Its totient is φ = 4988432384.

The previous prime is 7656377719. The next prime is 7656377749. The reversal of 7656377721 is 1277736567.

It is a cyclic number.

It is not a de Polignac number, because 7656377721 - 2¹ = 7656377719 is a prime.

It is a super-3 number, since 3×7656377721³ (a number of 31 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (7656377711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52821 + ... + 134546.

It is an arithmetic number, because the mean of its divisors is an integer number (652602744).

Almost surely, 2^7656377721 is an apocalyptic number.

It is an amenable number.

7656377721 is a deficient number, since it is larger than the sum of its proper divisors (2785266183).

7656377721 is a wasteful number, since it uses less digits than its factorization.

7656377721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187680.

The product of its digits is 2593080, while the sum is 51.

The square root of 7656377721 is about 87500.7298312420. The cubic root of 7656377721 is about 1970.9447503729.

The spelling of 7656377721 in words is "seven billion, six hundred fifty-six million, three hundred seventy-seven thousand, seven hundred twenty-one".