74727781 has 2 divisors, whose sum is σ = 74727782. Its totient is φ = 74727780.

The previous prime is 74727749. The next prime is 74727787. The reversal of 74727781 is 18772747.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49477156 + 25250625 = 7034^2 + 5025^2 .

It is a cyclic number.

It is not a de Polignac number, because 74727781 - 2⁵ = 74727749 is a prime.

It is a super-2 number, since 2×74727781² = 11168482506367922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74727787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37363890 + 37363891.

It is an arithmetic number, because the mean of its divisors is an integer number (37363891).

Almost surely, 2^74727781 is an apocalyptic number.

It is an amenable number.

74727781 is a deficient number, since it is larger than the sum of its proper divisors (1).

74727781 is an equidigital number, since it uses as much as digits as its factorization.

74727781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 153664, while the sum is 43.

The square root of 74727781 is about 8644.5231794472. The cubic root of 74727781 is about 421.2054954495.

The spelling of 74727781 in words is "seventy-four million, seven hundred twenty-seven thousand, seven hundred eighty-one".