78011491 has 4 divisors (see below), whose sum is σ = 78783984. Its totient is φ = 77239000.

The previous prime is 78011489. The next prime is 78011519. The reversal of 78011491 is 19411087.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78011491 - 2¹ = 78011489 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78011411) 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, 386095 + ... + 386296.

It is an arithmetic number, because the mean of its divisors is an integer number (19695996).

Almost surely, 2^78011491 is an apocalyptic number.

78011491 is a deficient number, since it is larger than the sum of its proper divisors (772493).

78011491 is a wasteful number, since it uses less digits than its factorization.

78011491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772492.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 78011491 is about 8832.4113921397. The cubic root of 78011491 is about 427.2868488151.

The spelling of 78011491 in words is "seventy-eight million, eleven thousand, four hundred ninety-one".