100421604 has 18 divisors (see below), whose sum is σ = 253843590. Its totient is φ = 33473856.

The previous prime is 100421603. The next prime is 100421623. The reversal of 100421604 is 406124001.

It can be written as a sum of positive squares in only one way, i.e., 91240704 + 9180900 = 9552^2 + 3030^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (100421603) 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 5 ways as a sum of consecutive naturals, for example, 1394709 + ... + 1394780.

Almost surely, 2^100421604 is an apocalyptic number.

It is an amenable number.

100421604 is an abundant number, since it is smaller than the sum of its proper divisors (153421986).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

100421604 is a wasteful number, since it uses less digits than its factorization.

100421604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2789499 (or 2789494 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 100421604 is about 10021.0580279729. The cubic root of 100421604 is about 464.8102729285.

Adding to 100421604 its reverse (406124001), we get a palindrome (506545605).

It can be divided in two parts, 100421 and 604, that added together give a triangular number (101025 = T₄₄₉).

The spelling of 100421604 in words is "one hundred million, four hundred twenty-one thousand, six hundred four".