78133209 has 48 divisors (see below), whose sum is σ = 132633984. Its totient is φ = 40043520.

The previous prime is 78133177. The next prime is 78133217. The reversal of 78133209 is 90233187.

It is not a de Polignac number, because 78133209 - 2⁵ = 78133177 is a prime.

It is a super-2 number, since 2×78133209² = 12209596697275362, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 78133209.

It is not an unprimeable number, because it can be changed into a prime (78133229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 246319 + ... + 246635.

It is an arithmetic number, because the mean of its divisors is an integer number (2763208).

Almost surely, 2^78133209 is an apocalyptic number.

It is an amenable number.

78133209 is a deficient number, since it is larger than the sum of its proper divisors (54500775).

78133209 is a wasteful number, since it uses less digits than its factorization.

78133209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 78133209 is about 8839.2991237994. The cubic root of 78133209 is about 427.5089591502.

The spelling of 78133209 in words is "seventy-eight million, one hundred thirty-three thousand, two hundred nine".