78291245 has 4 divisors (see below), whose sum is σ = 93949500. Its totient is φ = 62632992.

The previous prime is 78291209. The next prime is 78291247. The reversal of 78291245 is 54219287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54219287 = 4759 ⋅11393.

It can be written as a sum of positive squares in 2 ways, for example, as 62315236 + 15976009 = 7894^2 + 3997^2 .

It is a cyclic number.

It is not a de Polignac number, because 78291245 - 2¹⁶ = 78225709 is a prime.

It is a super-2 number, since 2×78291245² = 12259038087300050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78291199 and 78291208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78291247) 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, 7829120 + ... + 7829129.

It is an arithmetic number, because the mean of its divisors is an integer number (23487375).

Almost surely, 2^78291245 is an apocalyptic number.

It is an amenable number.

78291245 is a deficient number, since it is larger than the sum of its proper divisors (15658255).

78291245 is a wasteful number, since it uses less digits than its factorization.

78291245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15658254.

The product of its digits is 40320, while the sum is 38.

The square root of 78291245 is about 8848.2340045910. The cubic root of 78291245 is about 427.7969984555.

The spelling of 78291245 in words is "seventy-eight million, two hundred ninety-one thousand, two hundred forty-five".