78513151 has 4 divisors (see below), whose sum is σ = 78604992. Its totient is φ = 78421312.

The previous prime is 78513133. The next prime is 78513181. The reversal of 78513151 is 15131587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15131587 = 1879 ⋅8053.

It is a cyclic number.

It is not a de Polignac number, because 78513151 - 2⁷ = 78513023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78513181) 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, 44626 + ... + 46351.

It is an arithmetic number, because the mean of its divisors is an integer number (19651248).

Almost surely, 2^78513151 is an apocalyptic number.

78513151 is a deficient number, since it is larger than the sum of its proper divisors (91841).

78513151 is an equidigital number, since it uses as much as digits as its factorization.

78513151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91840.

The product of its digits is 4200, while the sum is 31.

The square root of 78513151 is about 8860.7646961196. The cubic root of 78513151 is about 428.2007948708.

It can be divided in two parts, 7 and 8513151, that added together give a palindrome (8513158).

The spelling of 78513151 in words is "seventy-eight million, five hundred thirteen thousand, one hundred fifty-one".