77861811 has 4 divisors (see below), whose sum is σ = 103815752. Its totient is φ = 51907872.

The previous prime is 77861783. The next prime is 77861837. The reversal of 77861811 is 11816877.

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

It is not a de Polignac number, because 77861811 - 2¹⁰ = 77860787 is a prime.

It is a super-2 number, since 2×77861811² = 12124923224399442, 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 77861811.

It is not an unprimeable number, because it can be changed into a prime (77861881) 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, 12976966 + ... + 12976971.

It is an arithmetic number, because the mean of its divisors is an integer number (25953938).

Almost surely, 2^77861811 is an apocalyptic number.

77861811 is a deficient number, since it is larger than the sum of its proper divisors (25953941).

77861811 is a wasteful number, since it uses less digits than its factorization.

77861811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25953940.

The product of its digits is 18816, while the sum is 39.

The square root of 77861811 is about 8823.9339866071. The cubic root of 77861811 is about 427.0133966074.

The spelling of 77861811 in words is "seventy-seven million, eight hundred sixty-one thousand, eight hundred eleven".