7771156420 has 24 divisors (see below), whose sum is σ = 16321123224. Its totient is φ = 3108139776.

The previous prime is 7771156373. The next prime is 7771156423. The reversal of 7771156420 is 246511777.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4466516224 + 3304640196 = 66832^2 + 57486^2 .

It is not an unprimeable number, because it can be changed into a prime (7771156423) 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 7 ways as a sum of consecutive naturals, for example, 305304 + ... + 329776.

It is an arithmetic number, because the mean of its divisors is an integer number (680046801).

Almost surely, 2^7771156420 is an apocalyptic number.

It is an amenable number.

7771156420 is an abundant number, since it is smaller than the sum of its proper divisors (8549966804).

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

7771156420 is a wasteful number, since it uses less digits than its factorization.

7771156420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40359 (or 40357 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 40.

The square root of 7771156420 is about 88154.1628058483. The cubic root of 7771156420 is about 1980.7449174802.

The spelling of 7771156420 in words is "seven billion, seven hundred seventy-one million, one hundred fifty-six thousand, four hundred twenty".