77421137 has 2 divisors, whose sum is σ = 77421138. Its totient is φ = 77421136.

The previous prime is 77421109. The next prime is 77421163. The reversal of 77421137 is 73112477.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75759616 + 1661521 = 8704^2 + 1289^2 .

It is a cyclic number.

It is not a de Polignac number, because 77421137 - 2⁶ = 77421073 is a prime.

It is not a weakly prime, because it can be changed into another prime (77421107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38710568 + 38710569.

It is an arithmetic number, because the mean of its divisors is an integer number (38710569).

Almost surely, 2^77421137 is an apocalyptic number.

It is an amenable number.

77421137 is a deficient number, since it is larger than the sum of its proper divisors (1).

77421137 is an equidigital number, since it uses as much as digits as its factorization.

77421137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8232, while the sum is 32.

The square root of 77421137 is about 8798.9281733629. The cubic root of 77421137 is about 426.2062836749.

The spelling of 77421137 in words is "seventy-seven million, four hundred twenty-one thousand, one hundred thirty-seven".