646425779 has 8 divisors (see below), whose sum is σ = 671359680. Its totient is φ = 621884736.

The previous prime is 646425761. The next prime is 646425797. The reversal of 646425779 is 977524646.

It is an interprime number because it is at equal distance from previous prime (646425761) and next prime (646425797).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646425779 - 2⁸ = 646425523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646425709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94859 + ... + 101444.

It is an arithmetic number, because the mean of its divisors is an integer number (83919960).

Almost surely, 2^646425779 is an apocalyptic number.

646425779 is a deficient number, since it is larger than the sum of its proper divisors (24933901).

646425779 is a wasteful number, since it uses less digits than its factorization.

646425779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196429.

The product of its digits is 2540160, while the sum is 50.

The square root of 646425779 is about 25424.9046999197. The cubic root of 646425779 is about 864.6484271855.

The spelling of 646425779 in words is "six hundred forty-six million, four hundred twenty-five thousand, seven hundred seventy-nine".