651720385 has 4 divisors (see below), whose sum is σ = 782064468. Its totient is φ = 521376304.

The previous prime is 651720367. The next prime is 651720437. The reversal of 651720385 is 583027156.

651720385 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.

It can be written as a sum of positive squares in 2 ways, for example, as 323712064 + 328008321 = 17992^2 + 18111^2 .

It is a cyclic number.

It is not a de Polignac number, because 651720385 - 2²⁵ = 618165953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65172034 + ... + 65172043.

It is an arithmetic number, because the mean of its divisors is an integer number (195516117).

Almost surely, 2^651720385 is an apocalyptic number.

It is an amenable number.

651720385 is a deficient number, since it is larger than the sum of its proper divisors (130344083).

651720385 is a wasteful number, since it uses less digits than its factorization.

651720385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130344082.

The product of its (nonzero) digits is 50400, while the sum is 37.

The square root of 651720385 is about 25528.8147981844. The cubic root of 651720385 is about 867.0026704224.

It can be divided in two parts, 6517203 and 85, that multiplied together give a triangular number (553962255 = T₃₃₂₈₅).

The spelling of 651720385 in words is "six hundred fifty-one million, seven hundred twenty thousand, three hundred eighty-five".