21023401 has 12 divisors (see below), whose sum is σ = 24769920. Its totient is φ = 17788680.

The previous prime is 21023393. The next prime is 21023413. The reversal of 21023401 is 10432012.

It is not a de Polignac number, because 21023401 - 2³ = 21023393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21023501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1156 + ... + 6586.

It is an arithmetic number, because the mean of its divisors is an integer number (2064160).

Almost surely, 2^21023401 is an apocalyptic number.

It is an amenable number.

21023401 is a deficient number, since it is larger than the sum of its proper divisors (3746519).

21023401 is an equidigital number, since it uses as much as digits as its factorization.

21023401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5524 (or 5517 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21023401 is about 4585.1282424813. The cubic root of 21023401 is about 275.9948583023.

Adding to 21023401 its reverse (10432012), we get a palindrome (31455413).

The spelling of 21023401 in words is "twenty-one million, twenty-three thousand, four hundred one".