78016401 has 6 divisors (see below), whose sum is σ = 112690370. Its totient is φ = 52010928.

The previous prime is 78016397. The next prime is 78016403. The reversal of 78016401 is 10461087.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 64883025 + 13133376 = 8055^2 + 3624^2 .

It is not a de Polignac number, because 78016401 - 2² = 78016397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78016403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4334236 + ... + 4334253.

Almost surely, 2^78016401 is an apocalyptic number.

It is an amenable number.

78016401 is a deficient number, since it is larger than the sum of its proper divisors (34673969).

78016401 is a wasteful number, since it uses less digits than its factorization.

78016401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8668495 (or 8668492 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 78016401 is about 8832.6893413048. The cubic root of 78016401 is about 427.2958130262.

Adding to 78016401 its reverse (10461087), we get a palindrome (88477488).

The spelling of 78016401 in words is "seventy-eight million, sixteen thousand, four hundred one".