78420771 has 64 divisors (see below), whose sum is σ = 143808000. Its totient is φ = 41523840.

The previous prime is 78420751. The next prime is 78420781. The reversal of 78420771 is 17702487.

It is not a de Polignac number, because 78420771 - 2¹⁷ = 78289699 is a prime.

It is a super-2 number, since 2×78420771² = 12299634648468882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78420721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 72825 + ... + 73893.

It is an arithmetic number, because the mean of its divisors is an integer number (2247000).

Almost surely, 2^78420771 is an apocalyptic number.

78420771 is a deficient number, since it is larger than the sum of its proper divisors (65387229).

78420771 is a wasteful number, since it uses less digits than its factorization.

78420771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1121 (or 1115 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 78420771 is about 8855.5502934600. The cubic root of 78420771 is about 428.0327860144.

The spelling of 78420771 in words is "seventy-eight million, four hundred twenty thousand, seven hundred seventy-one".