100321521 has 4 divisors (see below), whose sum is σ = 133762032. Its totient is φ = 66881012.

The previous prime is 100321499. The next prime is 100321523. The reversal of 100321521 is 125123001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125123001 = 3 ⋅41707667.

It is a cyclic number.

It is not a de Polignac number, because 100321521 - 2⁶ = 100321457 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 100321521.

It is not an unprimeable number, because it can be changed into a prime (100321523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16720251 + ... + 16720256.

It is an arithmetic number, because the mean of its divisors is an integer number (33440508).

Almost surely, 2^100321521 is an apocalyptic number.

It is an amenable number.

100321521 is a deficient number, since it is larger than the sum of its proper divisors (33440511).

100321521 is an equidigital number, since it uses as much as digits as its factorization.

100321521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33440510.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 100321521 is about 10016.0631487626. The cubic root of 100321521 is about 464.6558072641.

Adding to 100321521 its reverse (125123001), we get a palindrome (225444522).

It can be divided in two parts, 1003215 and 21, that added together give a triangular number (1003236 = T₁₄₁₆).

The spelling of 100321521 in words is "one hundred million, three hundred twenty-one thousand, five hundred twenty-one".