78120022111 has 4 divisors (see below), whose sum is σ = 78120745072. Its totient is φ = 78119299152.

The previous prime is 78120022087. The next prime is 78120022121. The reversal of 78120022111 is 11122002187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78120022111 - 2⁷ = 78120021983 is a prime.

It is a super-2 number, since 2×78120022111² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78120022121) 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, 163110 + ... + 427603.

It is an arithmetic number, because the mean of its divisors is an integer number (19530186268).

Almost surely, 2^78120022111 is an apocalyptic number.

78120022111 is a deficient number, since it is larger than the sum of its proper divisors (722961).

78120022111 is a wasteful number, since it uses less digits than its factorization.

78120022111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722960.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 78120022111 its reverse (11122002187), we get a palindrome (89242024298).

The spelling of 78120022111 in words is "seventy-eight billion, one hundred twenty million, twenty-two thousand, one hundred eleven".