100220521 has 4 divisors (see below), whose sum is σ = 100281412. Its totient is φ = 100159632.

The previous prime is 100220513. The next prime is 100220537. The reversal of 100220521 is 125022001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38378025 + 61842496 = 6195^2 + 7864^2 .

It is a cyclic number.

It is not a de Polignac number, because 100220521 - 2³ = 100220513 is a prime.

It is a super-2 number, since 2×100220521² = 20088305659022882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100220581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27906 + ... + 31291.

It is an arithmetic number, because the mean of its divisors is an integer number (25070353).

Almost surely, 2^100220521 is an apocalyptic number.

It is an amenable number.

100220521 is a deficient number, since it is larger than the sum of its proper divisors (60891).

100220521 is an equidigital number, since it uses as much as digits as its factorization.

100220521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60890.

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

The square root of 100220521 is about 10011.0199780042. The cubic root of 100220521 is about 464.4998221405.

Adding to 100220521 its reverse (125022001), we get a palindrome (225242522).

The spelling of 100220521 in words is "one hundred million, two hundred twenty thousand, five hundred twenty-one".