21926121 has 16 divisors (see below), whose sum is σ = 33481728. Its totient is φ = 12502800.

The previous prime is 21926077. The next prime is 21926123. The reversal of 21926121 is 12162912.

It is not a de Polignac number, because 21926121 - 2¹⁰ = 21925097 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21926091 and 21926100.

It is not an unprimeable number, because it can be changed into a prime (21926123) 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, 13756 + ... + 15266.

It is an arithmetic number, because the mean of its divisors is an integer number (2092608).

Almost surely, 2^21926121 is an apocalyptic number.

21926121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21926121 is a deficient number, since it is larger than the sum of its proper divisors (11555607).

21926121 is a wasteful number, since it uses less digits than its factorization.

21926121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2212.

The product of its digits is 432, while the sum is 24.

The square root of 21926121 is about 4682.5336090625. The cubic root of 21926121 is about 279.8899269721.

The spelling of 21926121 in words is "twenty-one million, nine hundred twenty-six thousand, one hundred twenty-one".