78199905 has 16 divisors (see below), whose sum is σ = 142994304. Its totient is φ = 35748480.

The previous prime is 78199889. The next prime is 78199937. The reversal of 78199905 is 50999187.

It is not a de Polignac number, because 78199905 - 2⁴ = 78199889 is a prime.

It is a super-2 number, since 2×78199905² = 12230450284018050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 372276 + ... + 372485.

It is an arithmetic number, because the mean of its divisors is an integer number (8937144).

Almost surely, 2^78199905 is an apocalyptic number.

It is an amenable number.

78199905 is a deficient number, since it is larger than the sum of its proper divisors (64794399).

78199905 is a wasteful number, since it uses less digits than its factorization.

78199905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744776.

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 78199905 is about 8843.0710163382. The cubic root of 78199905 is about 427.6305678260.

The spelling of 78199905 in words is "seventy-eight million, one hundred ninety-nine thousand, nine hundred five".