2621521 has 8 divisors (see below), whose sum is σ = 3006080. Its totient is φ = 2239488.

The previous prime is 2621501. The next prime is 2621527. The reversal of 2621521 is 1251262.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 4-Lehmer number, since φ(2621521) divides (2621521-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 2621521 - 2¹⁵ = 2588753 is a prime.

It is a super-3 number, since 3×2621521³ = 54048205333095011283, which contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (2621527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3025 + ... + 3793.

It is an arithmetic number, because the mean of its divisors is an integer number (375760).

2^2621521 is an apocalyptic number.

It is an amenable number.

2621521 is a deficient number, since it is larger than the sum of its proper divisors (384559).

2621521 is an equidigital number, since it uses as much as digits as its factorization.

2621521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1263.

The product of its digits is 240, while the sum is 19.

The square root of 2621521 is about 1619.1111759234. Note that the first 4 decimals coincide. The cubic root of 2621521 is about 137.8852403070.

Adding to 2621521 its reverse (1251262), we get a palindrome (3872783).

The spelling of 2621521 in words is "two million, six hundred twenty-one thousand, five hundred twenty-one".