21231011 has 8 divisors (see below), whose sum is σ = 22608720. Its totient is φ = 19867648.

The previous prime is 21230969. The next prime is 21231029. The reversal of 21231011 is 11013212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21231011 - 2⁶ = 21230947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230983 and 21231001.

It is not an unprimeable number, because it can be changed into a prime (21231611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 446 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (2826090).

Almost surely, 2^21231011 is an apocalyptic number.

21231011 is a deficient number, since it is larger than the sum of its proper divisors (1377709).

21231011 is a wasteful number, since it uses less digits than its factorization.

21231011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7173.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21231011 is about 4607.7121220840. The cubic root of 21231011 is about 276.9003842734.

Adding to 21231011 its reverse (11013212), we get a palindrome (32244223).

The spelling of 21231011 in words is "twenty-one million, two hundred thirty-one thousand, eleven".