764216645 has 4 divisors (see below), whose sum is σ = 917059980. Its totient is φ = 611373312.

The previous prime is 764216603. The next prime is 764216647. The reversal of 764216645 is 546612467.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 193293409 + 570923236 = 13903^2 + 23894^2 .

It is a cyclic number.

It is not a de Polignac number, because 764216645 - 2¹² = 764212549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (764216647) 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 in 3 ways as a sum of consecutive naturals, for example, 76421660 + ... + 76421669.

It is an arithmetic number, because the mean of its divisors is an integer number (229264995).

Almost surely, 2^764216645 is an apocalyptic number.

It is an amenable number.

764216645 is a deficient number, since it is larger than the sum of its proper divisors (152843335).

764216645 is a wasteful number, since it uses less digits than its factorization.

764216645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152843334.

The product of its digits is 241920, while the sum is 41.

The square root of 764216645 is about 27644.4686148965. The cubic root of 764216645 is about 914.2651469925.

The spelling of 764216645 in words is "seven hundred sixty-four million, two hundred sixteen thousand, six hundred forty-five".