3977771221 has 2 divisors, whose sum is σ = 3977771222. Its totient is φ = 3977771220.

The previous prime is 3977771141. The next prime is 3977771227. The reversal of 3977771221 is 1221777793.

3977771221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3682790596 + 294980625 = 60686^2 + 17175^2 .

It is an emirp because it is prime and its reverse (1221777793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3977771221 - 2²¹ = 3975674069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3977771227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1988885610 + 1988885611.

It is an arithmetic number, because the mean of its divisors is an integer number (1988885611).

Almost surely, 2^3977771221 is an apocalyptic number.

It is an amenable number.

3977771221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3977771221 is an equidigital number, since it uses as much as digits as its factorization.

3977771221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259308, while the sum is 46.

The square root of 3977771221 is about 63069.5744475892. The cubic root of 3977771221 is about 1584.4550891832.

The spelling of 3977771221 in words is "three billion, nine hundred seventy-seven million, seven hundred seventy-one thousand, two hundred twenty-one".