74776721 has 2 divisors, whose sum is σ = 74776722. Its totient is φ = 74776720.

The previous prime is 74776697. The next prime is 74776729. The reversal of 74776721 is 12767747.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74632321 + 144400 = 8639^2 + 380^2 .

It is an emirp because it is prime and its reverse (12767747) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 74776721 - 2¹⁸ = 74514577 is a prime.

It is not a weakly prime, because it can be changed into another prime (74776729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37388360 + 37388361.

It is an arithmetic number, because the mean of its divisors is an integer number (37388361).

Almost surely, 2^74776721 is an apocalyptic number.

It is an amenable number.

74776721 is a deficient number, since it is larger than the sum of its proper divisors (1).

74776721 is an equidigital number, since it uses as much as digits as its factorization.

74776721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 115248, while the sum is 41.

The square root of 74776721 is about 8647.3534101481. The cubic root of 74776721 is about 421.2974260017.

The spelling of 74776721 in words is "seventy-four million, seven hundred seventy-six thousand, seven hundred twenty-one".