77821113 has 4 divisors (see below), whose sum is σ = 103761488. Its totient is φ = 51880740.

The previous prime is 77821043. The next prime is 77821141. The reversal of 77821113 is 31112877.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31112877 = 3 ⋅10370959.

It is not a de Polignac number, because 77821113 - 2⁸ = 77820857 is a prime.

It is a super-2 number, since 2×77821113² = 12112251257117538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77821153) 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, 12970183 + ... + 12970188.

It is an arithmetic number, because the mean of its divisors is an integer number (25940372).

Almost surely, 2^77821113 is an apocalyptic number.

It is an amenable number.

77821113 is a deficient number, since it is larger than the sum of its proper divisors (25940375).

77821113 is a wasteful number, since it uses less digits than its factorization.

77821113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25940374.

The product of its digits is 2352, while the sum is 30.

The square root of 77821113 is about 8821.6275709191. The cubic root of 77821113 is about 426.9389843473.

The spelling of 77821113 in words is "seventy-seven million, eight hundred twenty-one thousand, one hundred thirteen".