77525221 has 2 divisors, whose sum is σ = 77525222. Its totient is φ = 77525220.

The previous prime is 77525209. The next prime is 77525257. The reversal of 77525221 is 12252577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77264100 + 261121 = 8790^2 + 511^2 .

It is a cyclic number.

It is not a de Polignac number, because 77525221 - 2⁷ = 77525093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77525521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38762610 + 38762611.

It is an arithmetic number, because the mean of its divisors is an integer number (38762611).

Almost surely, 2^77525221 is an apocalyptic number.

It is an amenable number.

77525221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77525221 is an equidigital number, since it uses as much as digits as its factorization.

77525221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9800, while the sum is 31.

The square root of 77525221 is about 8804.8407708487. The cubic root of 77525221 is about 426.3971935987.

Adding to 77525221 its reverse (12252577), we get a palindrome (89777798).

The spelling of 77525221 in words is "seventy-seven million, five hundred twenty-five thousand, two hundred twenty-one".