21051411 has 16 divisors (see below), whose sum is σ = 29769600. Its totient is φ = 13195008.

The previous prime is 21051403. The next prime is 21051421. The reversal of 21051411 is 11415012.

It is a happy number.

It is not a de Polignac number, because 21051411 - 2³ = 21051403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21051421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6595 + ... + 9251.

It is an arithmetic number, because the mean of its divisors is an integer number (1860600).

Almost surely, 2^21051411 is an apocalyptic number.

21051411 is a deficient number, since it is larger than the sum of its proper divisors (8718189).

21051411 is a wasteful number, since it uses less digits than its factorization.

21051411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2818.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 21051411 is about 4588.1816659762. The cubic root of 21051411 is about 276.1173755121.

Adding to 21051411 its reverse (11415012), we get a palindrome (32466423).

The spelling of 21051411 in words is "twenty-one million, fifty-one thousand, four hundred eleven".