653221678 has 4 divisors (see below), whose sum is σ = 979832520. Its totient is φ = 326610838.

The previous prime is 653221649. The next prime is 653221687. The reversal of 653221678 is 876122356.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 653221678.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163305418 + ... + 163305421.

It is an arithmetic number, because the mean of its divisors is an integer number (244958130).

Almost surely, 2^653221678 is an apocalyptic number.

653221678 is a deficient number, since it is larger than the sum of its proper divisors (326610842).

653221678 is a wasteful number, since it uses less digits than its factorization.

653221678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326610841.

The product of its digits is 120960, while the sum is 40.

The square root of 653221678 is about 25558.2017755553. The cubic root of 653221678 is about 867.6678978622.

The spelling of 653221678 in words is "six hundred fifty-three million, two hundred twenty-one thousand, six hundred seventy-eight".