387893541721 has 27 divisors (see below), whose sum is σ = 454559180733. Its totient is φ = 330040005120.

The previous prime is 387893541671. The next prime is 387893541743. The reversal of 387893541721 is 127145398783.

The square root of 387893541721 is 622811.

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

It can be written as a sum of positive squares in 4 ways, for example, as 74701089225 + 313192452496 = 273315^2 + 559636^2 .

It is not a de Polignac number, because 387893541721 - 2⁹ = 387893541209 is a prime.

It is a super-2 number, since 2×387893541721² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (387893541421) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 841417431 + ... + 841417891.

Almost surely, 2^387893541721 is an apocalyptic number.

387893541721 is the 622811-st square number.

387893541721 is the 311406-th centered octagonal number.

It is an amenable number.

387893541721 is a deficient number, since it is larger than the sum of its proper divisors (66665639012).

387893541721 is an frugal number, since it uses more digits than its factorization.

387893541721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322 (or 661 counting only the distinct ones).

The product of its digits is 10160640, while the sum is 58.

The spelling of 387893541721 in words is "three hundred eighty-seven billion, eight hundred ninety-three million, five hundred forty-one thousand, seven hundred twenty-one".