78421768 has 16 divisors (see below), whose sum is σ = 149815980. Its totient is φ = 38470848.

The previous prime is 78421757. The next prime is 78421769. The reversal of 78421768 is 86712487.

It can be written as a sum of positive squares in 2 ways, for example, as 68194564 + 10227204 = 8258^2 + 3198^2 .

It is a super-2 number, since 2×78421768² = 12299947392491648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78421769) 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, 92055 + ... + 92902.

Almost surely, 2^78421768 is an apocalyptic number.

It is an amenable number.

78421768 is a deficient number, since it is larger than the sum of its proper divisors (71394212).

78421768 is a wasteful number, since it uses less digits than its factorization.

78421768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185016 (or 185012 counting only the distinct ones).

The product of its digits is 150528, while the sum is 43.

The square root of 78421768 is about 8855.6065856609. The cubic root of 78421768 is about 428.0345999338.

The spelling of 78421768 in words is "seventy-eight million, four hundred twenty-one thousand, seven hundred sixty-eight".