21348121 has 4 divisors (see below), whose sum is σ = 21384244. Its totient is φ = 21312000.

The previous prime is 21348101. The next prime is 21348127. The reversal of 21348121 is 12184312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18147600 + 3200521 = 4260^2 + 1789^2 .

It is a cyclic number.

It is not a de Polignac number, because 21348121 - 2¹⁵ = 21315353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21348092 and 21348101.

It is not an unprimeable number, because it can be changed into a prime (21348127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17160 + ... + 18361.

It is an arithmetic number, because the mean of its divisors is an integer number (5346061).

Almost surely, 2^21348121 is an apocalyptic number.

It is an amenable number.

21348121 is a deficient number, since it is larger than the sum of its proper divisors (36123).

21348121 is an equidigital number, since it uses as much as digits as its factorization.

21348121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36122.

The product of its digits is 384, while the sum is 22.

The square root of 21348121 is about 4620.4026880782. The cubic root of 21348121 is about 277.4085774105.

The spelling of 21348121 in words is "twenty-one million, three hundred forty-eight thousand, one hundred twenty-one".