77721652 has 12 divisors (see below), whose sum is σ = 136338916. Its totient is φ = 38767680.

The previous prime is 77721649. The next prime is 77721661. The reversal of 77721652 is 25612777.

It can be written as a sum of positive squares in 2 ways, for example, as 31427236 + 46294416 = 5606^2 + 6804^2 .

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 21393 + ... + 24760.

Almost surely, 2^77721652 is an apocalyptic number.

It is an amenable number.

77721652 is a deficient number, since it is larger than the sum of its proper divisors (58617264).

77721652 is a wasteful number, since it uses less digits than its factorization.

77721652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46578 (or 46576 counting only the distinct ones).

The product of its digits is 41160, while the sum is 37.

The square root of 77721652 is about 8815.9884301194. The cubic root of 77721652 is about 426.7570205240.

The spelling of 77721652 in words is "seventy-seven million, seven hundred twenty-one thousand, six hundred fifty-two".