77669 has 4 divisors (see below), whose sum is σ = 78540. Its totient is φ = 76800.

The previous prime is 77659. The next prime is 77681. The reversal of 77669 is 96677.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 56644 + 21025 = 238^2 + 145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77669 is a prime.

It is a super-2 number, since 2×77669² = 12064947122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 284 + ... + 485.

It is an arithmetic number, because the mean of its divisors is an integer number (19635).

2⁷⁷⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

77669 is a deficient number, since it is larger than the sum of its proper divisors (871).

77669 is a wasteful number, since it uses less digits than its factorization.

77669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870.

The product of its digits is 15876, while the sum is 35.

The square root of 77669 is about 278.6915858077. The cubic root of 77669 is about 42.6660630882. Note that the first 3 decimals are identical.

The spelling of 77669 in words is "seventy-seven thousand, six hundred sixty-nine".