78215822 has 4 divisors (see below), whose sum is σ = 117323736. Its totient is φ = 39107910.

The previous prime is 78215791. The next prime is 78215833. The reversal of 78215822 is 22851287.

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

It is a super-2 number, since 2×78215822² = 12235429622271368, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19553954 + ... + 19553957.

It is an arithmetic number, because the mean of its divisors is an integer number (29330934).

Almost surely, 2^78215822 is an apocalyptic number.

78215822 is a deficient number, since it is larger than the sum of its proper divisors (39107914).

78215822 is a wasteful number, since it uses less digits than its factorization.

78215822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39107913.

The product of its digits is 17920, while the sum is 35.

The square root of 78215822 is about 8843.9709407031. The cubic root of 78215822 is about 427.6595795151.

The spelling of 78215822 in words is "seventy-eight million, two hundred fifteen thousand, eight hundred twenty-two".