21431011 has 8 divisors (see below), whose sum is σ = 24551424. Its totient is φ = 18325320.

The previous prime is 21430991. The next prime is 21431017. The reversal of 21431011 is 11013412.

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 21431011 - 2⁵ = 21430979 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21430982 and 21431000.

It is not an unprimeable number, because it can be changed into a prime (21431017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355 + ... + 6556.

It is an arithmetic number, because the mean of its divisors is an integer number (3068928).

Almost surely, 2^21431011 is an apocalyptic number.

21431011 is a deficient number, since it is larger than the sum of its proper divisors (3120413).

21431011 is an equidigital number, since it uses as much as digits as its factorization.

21431011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7361.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21431011 is about 4629.3639951942. The cubic root of 21431011 is about 277.7671522987.

Adding to 21431011 its reverse (11013412), we get a palindrome (32444423).

The spelling of 21431011 in words is "twenty-one million, four hundred thirty-one thousand, eleven".