100203021 has 16 divisors (see below), whose sum is σ = 149112000. Its totient is φ = 66503664.

The previous prime is 100203001. The next prime is 100203023. The reversal of 100203021 is 120302001.

It is a happy number.

It is not a de Polignac number, because 100203021 - 2⁶ = 100202957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 100202994 and 100203012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100203023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2046 + ... + 14303.

It is an arithmetic number, because the mean of its divisors is an integer number (9319500).

Almost surely, 2^100203021 is an apocalyptic number.

It is an amenable number.

100203021 is a deficient number, since it is larger than the sum of its proper divisors (48908979).

100203021 is a wasteful number, since it uses less digits than its factorization.

100203021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16585 (or 16579 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 100203021 is about 10010.1459030326. The cubic root of 100203021 is about 464.4727843642.

Adding to 100203021 its reverse (120302001), we get a palindrome (220505022).

It can be divided in two parts, 10020 and 3021, that added together give a triangular number (13041 = T₁₆₁).

The spelling of 100203021 in words is "one hundred million, two hundred three thousand, twenty-one".