78219997 has 8 divisors (see below), whose sum is σ = 79937280. Its totient is φ = 76511760.

The previous prime is 78219983. The next prime is 78220001. The reversal of 78219997 is 79991287.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78219997 - 2²³ = 69831389 is a prime.

It is a super-2 number, since 2×78219997² = 12236735861360018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78219497) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16972 + ... + 21082.

It is an arithmetic number, because the mean of its divisors is an integer number (9992160).

Almost surely, 2^78219997 is an apocalyptic number.

It is an amenable number.

78219997 is a deficient number, since it is larger than the sum of its proper divisors (1717283).

78219997 is a wasteful number, since it uses less digits than its factorization.

78219997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4523.

The product of its digits is 571536, while the sum is 52.

The square root of 78219997 is about 8844.2069740593. The cubic root of 78219997 is about 427.6671885765.

The spelling of 78219997 in words is "seventy-eight million, two hundred nineteen thousand, nine hundred ninety-seven".