387640721664 has 729 divisors, whose sum is σ = 1393904071287. Its totient is φ = 103283195904.

The previous prime is 387640721641. The next prime is 387640721701. The reversal of 387640721664 is 466127046783.

The square root of 387640721664 is 622608.

It is a perfect power (a square), and thus also a powerful number.

387640721664 is a `hidden beast` number, since 3 + 8 + 76 + 407 + 2 + 166 + 4 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 88422969600 + 299217752064 = 297360^2 + 547008^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 387640721664.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 3556336842 + ... + 3556336950.

Almost surely, 2^387640721664 is an apocalyptic number.

387640721664 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

387640721664 is the 622608-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 387640721664

387640721664 is an abundant number, since it is smaller than the sum of its proper divisors (1006263349623).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

387640721664 is a wasteful number, since it uses less digits than its factorization.

387640721664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 54.

The spelling of 387640721664 in words is "three hundred eighty-seven billion, six hundred forty million, seven hundred twenty-one thousand, six hundred sixty-four".