78354779 has 4 divisors (see below), whose sum is σ = 78880800. Its totient is φ = 77828760.

The previous prime is 78354761. The next prime is 78354791. The reversal of 78354779 is 97745387.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97745387 = 31 ⋅3153077.

It is a cyclic number.

It is not a de Polignac number, because 78354779 - 2¹⁶ = 78289243 is a prime.

It is a super-2 number, since 2×78354779² = 12278942784277682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78354379) 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, 262787 + ... + 263084.

It is an arithmetic number, because the mean of its divisors is an integer number (19720200).

Almost surely, 2^78354779 is an apocalyptic number.

78354779 is a deficient number, since it is larger than the sum of its proper divisors (526021).

78354779 is a wasteful number, since it uses less digits than its factorization.

78354779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526020.

The product of its digits is 1481760, while the sum is 50.

The square root of 78354779 is about 8851.8234844579. The cubic root of 78354779 is about 427.9126874474.

The spelling of 78354779 in words is "seventy-eight million, three hundred fifty-four thousand, seven hundred seventy-nine".