78020692091 has 4 divisors (see below), whose sum is σ = 78487882032. Its totient is φ = 77553502152.

The previous prime is 78020692073. The next prime is 78020692103. The reversal of 78020692091 is 19029602087.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19029602087 = 3001 ⋅6341087.

It is a cyclic number.

It is not a de Polignac number, because 78020692091 - 2¹⁸ = 78020429947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78020692051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233594720 + ... + 233595053.

It is an arithmetic number, because the mean of its divisors is an integer number (19621970508).

Almost surely, 2^78020692091 is an apocalyptic number.

78020692091 is a deficient number, since it is larger than the sum of its proper divisors (467189941).

78020692091 is a wasteful number, since it uses less digits than its factorization.

78020692091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467189940.

The product of its (nonzero) digits is 108864, while the sum is 44.

The spelling of 78020692091 in words is "seventy-eight billion, twenty million, six hundred ninety-two thousand, ninety-one".