77275021 has 2 divisors, whose sum is σ = 77275022. Its totient is φ = 77275020.

The previous prime is 77275001. The next prime is 77275027. The reversal of 77275021 is 12057277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77193796 + 81225 = 8786^2 + 285^2 .

It is a cyclic number.

It is not a de Polignac number, because 77275021 - 2⁷ = 77274893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77275027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38637510 + 38637511.

It is an arithmetic number, because the mean of its divisors is an integer number (38637511).

Almost surely, 2^77275021 is an apocalyptic number.

It is an amenable number.

77275021 is a deficient number, since it is larger than the sum of its proper divisors (1).

77275021 is an equidigital number, since it uses as much as digits as its factorization.

77275021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6860, while the sum is 31.

The square root of 77275021 is about 8790.6211953422. The cubic root of 77275021 is about 425.9379901218.

The spelling of 77275021 in words is "seventy-seven million, two hundred seventy-five thousand, twenty-one".