7521381 has 24 divisors (see below), whose sum is σ = 12489984. Its totient is φ = 4272480.

The previous prime is 7521373. The next prime is 7521383. The reversal of 7521381 is 1831257.

7521381 is a nontrivial binomial coefficient, being equal to C(3879, 2).

It is not a de Polignac number, because 7521381 - 2³ = 7521373 is a prime.

It is a super-2 number, since 2×7521381² = 113142344294322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7521383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17236 + ... + 17666.

It is an arithmetic number, because the mean of its divisors is an integer number (520416).

Almost surely, 2^7521381 is an apocalyptic number.

7521381 is the 3878-th triangular number.

It is an amenable number.

7521381 is a deficient number, since it is larger than the sum of its proper divisors (4968603).

7521381 is a wasteful number, since it uses less digits than its factorization.

7521381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721 (or 718 counting only the distinct ones).

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

The square root of 7521381 is about 2742.5136280427. The cubic root of 7521381 is about 195.9292139915.

The spelling of 7521381 in words is "seven million, five hundred twenty-one thousand, three hundred eighty-one".