78131601 has 8 divisors (see below), whose sum is σ = 115750560. Its totient is φ = 52087716.

The previous prime is 78131569. The next prime is 78131623. The reversal of 78131601 is 10613187.

It is not a de Polignac number, because 78131601 - 2⁵ = 78131569 is a prime.

It is a super-2 number, since 2×78131601² = 12209094149646402, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2893763 = 78131601 / (7 + 8 + 1 + 3 + 1 + 6 + 0 + 1).

It is not an unprimeable number, because it can be changed into a prime (78131671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1446855 + ... + 1446908.

It is an arithmetic number, because the mean of its divisors is an integer number (14468820).

Almost surely, 2^78131601 is an apocalyptic number.

It is an amenable number.

78131601 is a deficient number, since it is larger than the sum of its proper divisors (37618959).

78131601 is a wasteful number, since it uses less digits than its factorization.

78131601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2893772 (or 2893766 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 78131601 is about 8839.2081658936. The cubic root of 78131601 is about 427.5060263847.

Adding to 78131601 its reverse (10613187), we get a palindrome (88744788).

The spelling of 78131601 in words is "seventy-eight million, one hundred thirty-one thousand, six hundred one".