78365811 has 4 divisors (see below), whose sum is σ = 104487752. Its totient is φ = 52243872.

The previous prime is 78365809. The next prime is 78365821. The reversal of 78365811 is 11856387.

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

It is not a de Polignac number, because 78365811 - 2¹ = 78365809 is a prime.

It is a super-2 number, since 2×78365811² = 12282400667375442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78365811.

It is not an unprimeable number, because it can be changed into a prime (78365821) 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, 13060966 + ... + 13060971.

It is an arithmetic number, because the mean of its divisors is an integer number (26121938).

Almost surely, 2^78365811 is an apocalyptic number.

78365811 is a deficient number, since it is larger than the sum of its proper divisors (26121941).

78365811 is a wasteful number, since it uses less digits than its factorization.

78365811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26121940.

The product of its digits is 40320, while the sum is 39.

The square root of 78365811 is about 8852.4466109658. The cubic root of 78365811 is about 427.9327692314.

The spelling of 78365811 in words is "seventy-eight million, three hundred sixty-five thousand, eight hundred eleven".