78537161 has 4 divisors (see below), whose sum is σ = 83157012. Its totient is φ = 73917312.

The previous prime is 78537119. The next prime is 78537163. The reversal of 78537161 is 16173587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16173587 = 71 ⋅227797.

It can be written as a sum of positive squares in 2 ways, for example, as 72505225 + 6031936 = 8515^2 + 2456^2 .

It is a cyclic number.

It is not a de Polignac number, because 78537161 - 2⁶ = 78537097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78537163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2309900 + ... + 2309933.

It is an arithmetic number, because the mean of its divisors is an integer number (20789253).

Almost surely, 2^78537161 is an apocalyptic number.

It is an amenable number.

78537161 is a deficient number, since it is larger than the sum of its proper divisors (4619851).

78537161 is a wasteful number, since it uses less digits than its factorization.

78537161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4619850.

The product of its digits is 35280, while the sum is 38.

The square root of 78537161 is about 8862.1194417588. The cubic root of 78537161 is about 428.2444395898.

The spelling of 78537161 in words is "seventy-eight million, five hundred thirty-seven thousand, one hundred sixty-one".