78235661 has 16 divisors (see below), whose sum is σ = 92651520. Its totient is φ = 64646640.

The previous prime is 78235657. The next prime is 78235669. The reversal of 78235661 is 16653287.

It is a cyclic number.

It is not a de Polignac number, because 78235661 - 2² = 78235657 is a prime.

It is a super-2 number, since 2×78235661² = 12241637304213842, which contains 22 as substring.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78235669) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 74780 + ... + 75818.

It is an arithmetic number, because the mean of its divisors is an integer number (5790720).

Almost surely, 2^78235661 is an apocalyptic number.

It is an amenable number.

78235661 is a deficient number, since it is larger than the sum of its proper divisors (14415859).

78235661 is a wasteful number, since it uses less digits than its factorization.

78235661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424.

The product of its digits is 60480, while the sum is 38.

The square root of 78235661 is about 8845.0924811446. The cubic root of 78235661 is about 427.6957342681.

The spelling of 78235661 in words is "seventy-eight million, two hundred thirty-five thousand, six hundred sixty-one".