653978345 has 4 divisors (see below), whose sum is σ = 784774020. Its totient is φ = 523182672.

The previous prime is 653978341. The next prime is 653978383. The reversal of 653978345 is 543879356.

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

It can be written as a sum of positive squares in 2 ways, for example, as 235530409 + 418447936 = 15347^2 + 20456^2 .

It is a cyclic number.

It is not a de Polignac number, because 653978345 - 2² = 653978341 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 653978293 and 653978302.

It is not an unprimeable number, because it can be changed into a prime (653978341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65397830 + ... + 65397839.

It is an arithmetic number, because the mean of its divisors is an integer number (196193505).

Almost surely, 2^653978345 is an apocalyptic number.

It is an amenable number.

653978345 is a deficient number, since it is larger than the sum of its proper divisors (130795675).

653978345 is a wasteful number, since it uses less digits than its factorization.

653978345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130795674.

The product of its digits is 2721600, while the sum is 50.

The square root of 653978345 is about 25573.0003128299. Note that the first 3 decimals coincide. The cubic root of 653978345 is about 868.0027930177.

The spelling of 653978345 in words is "six hundred fifty-three million, nine hundred seventy-eight thousand, three hundred forty-five".