78206811 has 4 divisors (see below), whose sum is σ = 104275752. Its totient is φ = 52137872.

The previous prime is 78206759. The next prime is 78206827. The reversal of 78206811 is 11860287.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78206811 - 2²² = 74012507 is a prime.

It is a super-2 number, since 2×78206811² = 12232610573579442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78205811) 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, 13034466 + ... + 13034471.

It is an arithmetic number, because the mean of its divisors is an integer number (26068938).

Almost surely, 2^78206811 is an apocalyptic number.

78206811 is a deficient number, since it is larger than the sum of its proper divisors (26068941).

78206811 is a wasteful number, since it uses less digits than its factorization.

78206811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26068940.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 78206811 is about 8843.4614829262. The cubic root of 78206811 is about 427.6431557773.

The spelling of 78206811 in words is "seventy-eight million, two hundred six thousand, eight hundred eleven".