21411291 has 32 divisors (see below), whose sum is σ = 32440320. Its totient is φ = 12448800.

The previous prime is 21411287. The next prime is 21411301. The reversal of 21411291 is 19211412.

21411291 = 19² + 20² + ... + 400².

It is a happy number.

It is not a de Polignac number, because 21411291 - 2² = 21411287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21411241) 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, 112006 + ... + 112196.

It is an arithmetic number, because the mean of its divisors is an integer number (1013760).

Almost surely, 2^21411291 is an apocalyptic number.

21411291 is a deficient number, since it is larger than the sum of its proper divisors (11029029).

21411291 is a wasteful number, since it uses less digits than its factorization.

21411291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327.

The product of its digits is 144, while the sum is 21.

The square root of 21411291 is about 4627.2336228032. The cubic root of 21411291 is about 277.6819292360.

The spelling of 21411291 in words is "twenty-one million, four hundred eleven thousand, two hundred ninety-one".