78121071 has 32 divisors (see below), whose sum is σ = 133585920. Its totient is φ = 44196192.

The previous prime is 78121051. The next prime is 78121073. The reversal of 78121071 is 17012187.

It is not a de Polignac number, because 78121071 - 2⁵ = 78121039 is a prime.

It is a super-2 number, since 2×78121071² = 12205803468374082, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78121073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17461 + ... + 21473.

It is an arithmetic number, because the mean of its divisors is an integer number (4174560).

Almost surely, 2^78121071 is an apocalyptic number.

78121071 is a deficient number, since it is larger than the sum of its proper divisors (55464849).

78121071 is a wasteful number, since it uses less digits than its factorization.

78121071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132 (or 4126 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 27.

The square root of 78121071 is about 8838.6125042339. The cubic root of 78121071 is about 427.4868201538.

The spelling of 78121071 in words is "seventy-eight million, one hundred twenty-one thousand, seventy-one".