78895661 has 4 divisors (see below), whose sum is σ = 84964572. Its totient is φ = 72826752.

The previous prime is 78895633. The next prime is 78895673. The reversal of 78895661 is 16659887.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16659887 = 109 ⋅152843.

It can be written as a sum of positive squares in 2 ways, for example, as 31147561 + 47748100 = 5581^2 + 6910^2 .

It is a cyclic number.

It is not a de Polignac number, because 78895661 - 2²² = 74701357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78895361) 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, 3034436 + ... + 3034461.

It is an arithmetic number, because the mean of its divisors is an integer number (21241143).

Almost surely, 2^78895661 is an apocalyptic number.

It is an amenable number.

78895661 is a deficient number, since it is larger than the sum of its proper divisors (6068911).

78895661 is a wasteful number, since it uses less digits than its factorization.

78895661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6068910.

The product of its digits is 725760, while the sum is 50.

The square root of 78895661 is about 8882.3229506701. The cubic root of 78895661 is about 428.8950556797.

The spelling of 78895661 in words is "seventy-eight million, eight hundred ninety-five thousand, six hundred sixty-one".