10100021 has 4 divisors (see below), whose sum is σ = 10221792. Its totient is φ = 9978252.

The previous prime is 10100011. The next prime is 10100047. The reversal of 10100021 is 12000101.

It is a happy number.

10100021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10100021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 10099978 and 10100014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10100011) 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, 60761 + ... + 60926.

It is an arithmetic number, because the mean of its divisors is an integer number (2555448).

Almost surely, 2^10100021 is an apocalyptic number.

It is an amenable number.

10100021 is a deficient number, since it is larger than the sum of its proper divisors (121771).

10100021 is an equidigital number, since it uses as much as digits as its factorization.

10100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121770.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 10100021 is about 3178.0530203255. The cubic root of 10100021 is about 216.1593831077.

Adding to 10100021 its reverse (12000101), we get a palindrome (22100122).

Multiplying 10100021 by its reverse (12000101), we get a palindrome (121201272102121).

The spelling of 10100021 in words is "ten million, one hundred thousand, twenty-one".