78572221 has 16 divisors (see below), whose sum is σ = 98074368. Its totient is φ = 61286400.

The previous prime is 78572213. The next prime is 78572257. The reversal of 78572221 is 12227587.

It is not a de Polignac number, because 78572221 - 2³ = 78572213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78572261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 381 + ... + 12541.

It is an arithmetic number, because the mean of its divisors is an integer number (6129648).

Almost surely, 2^78572221 is an apocalyptic number.

78572221 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

78572221 is a deficient number, since it is larger than the sum of its proper divisors (19502147).

78572221 is a wasteful number, since it uses less digits than its factorization.

78572221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12252.

The product of its digits is 15680, while the sum is 34.

The square root of 78572221 is about 8864.0973031663. The cubic root of 78572221 is about 428.3081547205.

The spelling of 78572221 in words is "seventy-eight million, five hundred seventy-two thousand, two hundred twenty-one".