77233721 has 2 divisors, whose sum is σ = 77233722. Its totient is φ = 77233720.

The previous prime is 77233661. The next prime is 77233759. The reversal of 77233721 is 12733277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76650025 + 583696 = 8755^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 77233721 - 2⁶ = 77233657 is a prime.

It is not a weakly prime, because it can be changed into another prime (77233021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38616860 + 38616861.

It is an arithmetic number, because the mean of its divisors is an integer number (38616861).

Almost surely, 2^77233721 is an apocalyptic number.

It is an amenable number.

77233721 is a deficient number, since it is larger than the sum of its proper divisors (1).

77233721 is an equidigital number, since it uses as much as digits as its factorization.

77233721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12348, while the sum is 32.

The square root of 77233721 is about 8788.2717868760. The cubic root of 77233721 is about 425.8620950758.

Adding to 77233721 its reverse (12733277), we get a palindrome (89966998).

The spelling of 77233721 in words is "seventy-seven million, two hundred thirty-three thousand, seven hundred twenty-one".