21023101 has 32 divisors (see below), whose sum is σ = 26248320. Its totient is φ = 16588800.

The previous prime is 21023099. The next prime is 21023111. The reversal of 21023101 is 10132012.

It is a 7-Lehmer number, since φ(21023101) divides (21023101-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 21023101 - 2¹ = 21023099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 216685 + ... + 216781.

It is an arithmetic number, because the mean of its divisors is an integer number (820260).

Almost surely, 2^21023101 is an apocalyptic number.

It is an amenable number.

21023101 is a deficient number, since it is larger than the sum of its proper divisors (5225219).

21023101 is a wasteful number, since it uses less digits than its factorization.

21023101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21023101 is about 4585.0955279034. The cubic root of 21023101 is about 275.9935454977.

Adding to 21023101 its reverse (10132012), we get a palindrome (31155113).

The spelling of 21023101 in words is "twenty-one million, twenty-three thousand, one hundred one".