7475777721 has 24 divisors (see below), whose sum is σ = 10874223360. Its totient is φ = 4948887456.

The previous prime is 7475777719. The next prime is 7475777737. The reversal of 7475777721 is 1277775747.

7475777721 is a `hidden beast` number, since 7 + 47 + 577 + 7 + 7 + 21 = 666.

It is not a de Polignac number, because 7475777721 - 2¹ = 7475777719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7475777521) 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 23 ways as a sum of consecutive naturals, for example, 3236515 + ... + 3238823.

It is an arithmetic number, because the mean of its divisors is an integer number (453092640).

Almost surely, 2^7475777721 is an apocalyptic number.

It is an amenable number.

7475777721 is a deficient number, since it is larger than the sum of its proper divisors (3398445639).

7475777721 is a wasteful number, since it uses less digits than its factorization.

7475777721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4685 (or 4682 counting only the distinct ones).

The product of its digits is 4705960, while the sum is 54.

The square root of 7475777721 is about 86462.5798886432. The cubic root of 7475777721 is about 1955.3242809081.

The spelling of 7475777721 in words is "seven billion, four hundred seventy-five million, seven hundred seventy-seven thousand, seven hundred twenty-one".