77761661 has 8 divisors (see below), whose sum is σ = 82225920. Its totient is φ = 73334592.

The previous prime is 77761627. The next prime is 77761681. The reversal of 77761661 is 16616777.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77761661 - 2¹⁸ = 77499517 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77761681) 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 7 ways as a sum of consecutive naturals, for example, 4940 + ... + 13413.

It is an arithmetic number, because the mean of its divisors is an integer number (10278240).

Almost surely, 2^77761661 is an apocalyptic number.

It is an amenable number.

77761661 is a deficient number, since it is larger than the sum of its proper divisors (4464259).

77761661 is a wasteful number, since it uses less digits than its factorization.

77761661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18595.

The product of its digits is 74088, while the sum is 41.

The square root of 77761661 is about 8818.2572541291. The cubic root of 77761661 is about 426.8302356117.

The spelling of 77761661 in words is "seventy-seven million, seven hundred sixty-one thousand, six hundred sixty-one".