646207951 has 4 divisors (see below), whose sum is σ = 647273152. Its totient is φ = 645142752.

The previous prime is 646207949. The next prime is 646207963. The reversal of 646207951 is 159702646.

646207951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 159702646 = 2 ⋅79851323.

It is a cyclic number.

It is not a de Polignac number, because 646207951 - 2¹ = 646207949 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 (646207921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531690 + ... + 532903.

It is an arithmetic number, because the mean of its divisors is an integer number (161818288).

Almost surely, 2^646207951 is an apocalyptic number.

646207951 is a deficient number, since it is larger than the sum of its proper divisors (1065201).

646207951 is a wasteful number, since it uses less digits than its factorization.

646207951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065200.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 646207951 is about 25420.6205864452. The cubic root of 646207951 is about 864.5512952314.

The spelling of 646207951 in words is "six hundred forty-six million, two hundred seven thousand, nine hundred fifty-one".