7138521 has 48 divisors (see below), whose sum is σ = 12199824. Its totient is φ = 3981312.

The previous prime is 7138513. The next prime is 7138541. The reversal of 7138521 is 1258317.

7138521 is a `hidden beast` number, since 7 + 138 + 521 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 168921 + 6969600 = 411^2 + 2640^2 .

It is not a de Polignac number, because 7138521 - 2³ = 7138513 is a prime.

7138521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7138541) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73545 + ... + 73641.

It is an arithmetic number, because the mean of its divisors is an integer number (254163).

Almost surely, 2^7138521 is an apocalyptic number.

It is an amenable number.

7138521 is a deficient number, since it is larger than the sum of its proper divisors (5061303).

7138521 is a wasteful number, since it uses less digits than its factorization.

7138521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 167 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 7138521 is about 2671.8010779248. The cubic root of 7138521 is about 192.5467003130.

The spelling of 7138521 in words is "seven million, one hundred thirty-eight thousand, five hundred twenty-one".