78435221 has 16 divisors (see below), whose sum is σ = 83655936. Its totient is φ = 73387776.

The previous prime is 78435209. The next prime is 78435223. The reversal of 78435221 is 12253487.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78435221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78435223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267551 + ... + 267843.

It is an arithmetic number, because the mean of its divisors is an integer number (5228496).

Almost surely, 2^78435221 is an apocalyptic number.

It is an amenable number.

78435221 is a deficient number, since it is larger than the sum of its proper divisors (5220715).

78435221 is a wasteful number, since it uses less digits than its factorization.

78435221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532.

The product of its digits is 13440, while the sum is 32.

The square root of 78435221 is about 8856.3661283847. The cubic root of 78435221 is about 428.0590745169.

The spelling of 78435221 in words is "seventy-eight million, four hundred thirty-five thousand, two hundred twenty-one".