100400521 has 16 divisors (see below), whose sum is σ = 115290000. Its totient is φ = 86611968.

The previous prime is 100400491. The next prime is 100400527. The reversal of 100400521 is 125004001.

It can be written as a sum of positive squares in 8 ways, for example, as 22325625 + 78074896 = 4725^2 + 8836^2 .

It is a cyclic number.

It is not a de Polignac number, because 100400521 - 2⁷ = 100400393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100400527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31405 + ... + 34453.

It is an arithmetic number, because the mean of its divisors is an integer number (7205625).

Almost surely, 2^100400521 is an apocalyptic number.

It is an amenable number.

100400521 is a deficient number, since it is larger than the sum of its proper divisors (14889479).

100400521 is a wasteful number, since it uses less digits than its factorization.

100400521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3228.

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

The square root of 100400521 is about 10020.0060379223. The cubic root of 100400521 is about 464.7777424754. Note that the first 4 decimals are identical.

Adding to 100400521 its reverse (125004001), we get a palindrome (225404522).

The spelling of 100400521 in words is "one hundred million, four hundred thousand, five hundred twenty-one".