78390951 has 4 divisors (see below), whose sum is σ = 104521272. Its totient is φ = 52260632.

The previous prime is 78390899. The next prime is 78390953. The reversal of 78390951 is 15909387.

It is a happy number.

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 78390951 - 2⁹ = 78390439 is a prime.

It is a super-2 number, since 2×78390951² = 12290282397368802, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78390953) 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, 13065156 + ... + 13065161.

It is an arithmetic number, because the mean of its divisors is an integer number (26130318).

Almost surely, 2^78390951 is an apocalyptic number.

78390951 is a deficient number, since it is larger than the sum of its proper divisors (26130321).

78390951 is a wasteful number, since it uses less digits than its factorization.

78390951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26130320.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 78390951 is about 8853.8664435375. The cubic root of 78390951 is about 427.9785250674.

The spelling of 78390951 in words is "seventy-eight million, three hundred ninety thousand, nine hundred fifty-one".