386648919721 has 9 divisors (see below), whose sum is σ = 390503923191. Its totient is φ = 382831621992.

The previous prime is 386648919697. The next prime is 386648919799. The reversal of 386648919721 is 127919846683.

The square root of 386648919721 is 621811.

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

It can be written as a sum of positive squares in only one way, i.e., 75914025625 + 310734894096 = 275525^2 + 557436^2 .

It is not a de Polignac number, because 386648919721 - 2¹¹ = 386648917673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (386648911721) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 64043515 + ... + 64049551.

It is an arithmetic number, because the mean of its divisors is an integer number (43389324799).

Almost surely, 2^386648919721 is an apocalyptic number.

386648919721 is the 621811-st square number.

386648919721 is the 310906-th centered octagonal number.

It is an amenable number.

386648919721 is a deficient number, since it is larger than the sum of its proper divisors (3855003470).

386648919721 is an frugal number, since it uses more digits than its factorization.

386648919721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12280 (or 6140 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 64.

Multiplying 386648919721 by its sum of digits (64), we get a square (24745530862144 = 4974488²).

The spelling of 386648919721 in words is "three hundred eighty-six billion, six hundred forty-eight million, nine hundred nineteen thousand, seven hundred twenty-one".