388521 has 18 divisors (see below), whose sum is σ = 653562. Its totient is φ = 221760.

The previous prime is 388519. The next prime is 388529. The reversal of 388521 is 125883.

It is a happy number.

388521 is a nontrivial binomial coefficient, being equal to C(882, 2).

It can be written as a sum of positive squares in only one way, i.e., 275625 + 112896 = 525^2 + 336^2 .

It is not a de Polignac number, because 388521 - 2¹ = 388519 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (388529) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1 + ... + 881.

It is an arithmetic number, because the mean of its divisors is an integer number (36309).

2³⁸⁸⁵²¹ is an apocalyptic number.

388521 is the 881-st triangular number and also the 441-st hexagonal number.

It is an amenable number.

388521 is a deficient number, since it is larger than the sum of its proper divisors (265041).

388521 is a wasteful number, since it uses less digits than its factorization.

388521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901 (or 891 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 388521 is about 623.3145273455. The cubic root of 388521 is about 72.9689615969.

It can be divided in two parts, 388 and 521, that added together give a palindrome (909).

The spelling of 388521 in words is "three hundred eighty-eight thousand, five hundred twenty-one".