22001521 has 8 divisors (see below), whose sum is σ = 22336704. Its totient is φ = 21668880.

The previous prime is 22001503. The next prime is 22001533. The reversal of 22001521 is 12510022.

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

It is a cyclic number.

It is not a de Polignac number, because 22001521 - 2¹⁵ = 21968753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22001321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22911 + ... + 23851.

It is an arithmetic number, because the mean of its divisors is an integer number (2792088).

Almost surely, 2^22001521 is an apocalyptic number.

It is an amenable number.

22001521 is a deficient number, since it is larger than the sum of its proper divisors (335183).

22001521 is a wasteful number, since it uses less digits than its factorization.

22001521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1271.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 22001521 is about 4690.5778961659. The cubic root of 22001521 is about 280.2103903437.

Adding to 22001521 its reverse (12510022), we get a palindrome (34511543).

It can be divided in two parts, 22001 and 521, that added together give a palindrome (22522).

The spelling of 22001521 in words is "twenty-two million, one thousand, five hundred twenty-one".