78921235 has 4 divisors (see below), whose sum is σ = 94705488. Its totient is φ = 63136984.

The previous prime is 78921221. The next prime is 78921239. The reversal of 78921235 is 53212987.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78921235 is a prime.

It is a super-2 number, since 2×78921235² = 12457122667850450, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78921194 and 78921203.

It is not an unprimeable number, because it can be changed into a prime (78921239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7892119 + ... + 7892128.

It is an arithmetic number, because the mean of its divisors is an integer number (23676372).

Almost surely, 2^78921235 is an apocalyptic number.

78921235 is a deficient number, since it is larger than the sum of its proper divisors (15784253).

78921235 is a wasteful number, since it uses less digits than its factorization.

78921235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15784252.

The product of its digits is 30240, while the sum is 37.

The square root of 78921235 is about 8883.7624349146. The cubic root of 78921235 is about 428.9413927324.

The spelling of 78921235 in words is "seventy-eight million, nine hundred twenty-one thousand, two hundred thirty-five".