77321661 has 24 divisors (see below), whose sum is σ = 110726304. Its totient is φ = 47980800.

The previous prime is 77321641. The next prime is 77321677. The reversal of 77321661 is 16612377.

It is not a de Polignac number, because 77321661 - 2⁶ = 77321597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77321641) 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 in 23 ways as a sum of consecutive naturals, for example, 87126 + ... + 88008.

It is an arithmetic number, because the mean of its divisors is an integer number (4613596).

Almost surely, 2^77321661 is an apocalyptic number.

It is an amenable number.

77321661 is a deficient number, since it is larger than the sum of its proper divisors (33404643).

77321661 is a wasteful number, since it uses less digits than its factorization.

77321661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1021 (or 1004 counting only the distinct ones).

The product of its digits is 10584, while the sum is 33.

The square root of 77321661 is about 8793.2736224912. The cubic root of 77321661 is about 426.0236657266.

The spelling of 77321661 in words is "seventy-seven million, three hundred twenty-one thousand, six hundred sixty-one".