78717947 has 32 divisors (see below), whose sum is σ = 101122560. Its totient is φ = 59512320.

The previous prime is 78717943. The next prime is 78717979. The reversal of 78717947 is 74971787.

It is not a de Polignac number, because 78717947 - 2² = 78717943 is a prime.

It is a super-3 number, since 3×78717947³ (a number of 25 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78717895 and 78717904.

It is not an unprimeable number, because it can be changed into a prime (78717943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 696563 + ... + 696675.

It is an arithmetic number, because the mean of its divisors is an integer number (3160080).

Almost surely, 2^78717947 is an apocalyptic number.

78717947 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

78717947 is a deficient number, since it is larger than the sum of its proper divisors (22404613).

78717947 is a wasteful number, since it uses less digits than its factorization.

78717947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323.

The product of its digits is 691488, while the sum is 50.

The square root of 78717947 is about 8872.3135088882. The cubic root of 78717947 is about 428.5727821174.

The spelling of 78717947 in words is "seventy-eight million, seven hundred seventeen thousand, nine hundred forty-seven".