77921471 has 2 divisors, whose sum is σ = 77921472. Its totient is φ = 77921470.

The previous prime is 77921429. The next prime is 77921483. The reversal of 77921471 is 17412977.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77921471 - 2⁶ = 77921407 is a prime.

It is a super-3 number, since 3×77921471³ (a number of 25 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77921411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38960735 + 38960736.

It is an arithmetic number, because the mean of its divisors is an integer number (38960736).

Almost surely, 2^77921471 is an apocalyptic number.

77921471 is a deficient number, since it is larger than the sum of its proper divisors (1).

77921471 is an equidigital number, since it uses as much as digits as its factorization.

77921471 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24696, while the sum is 38.

The square root of 77921471 is about 8827.3139176082. The cubic root of 77921471 is about 427.1224321537.

The spelling of 77921471 in words is "seventy-seven million, nine hundred twenty-one thousand, four hundred seventy-one".