21514421 has 2 divisors, whose sum is σ = 21514422. Its totient is φ = 21514420.

The previous prime is 21514399. The next prime is 21514429. The reversal of 21514421 is 12441512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21031396 + 483025 = 4586^2 + 695^2 .

It is a cyclic number.

It is not a de Polignac number, because 21514421 - 2²² = 17320117 is a prime.

It is a super-3 number, since 3×21514421³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21514393 and 21514402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21514429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757210 + 10757211.

It is an arithmetic number, because the mean of its divisors is an integer number (10757211).

Almost surely, 2^21514421 is an apocalyptic number.

It is an amenable number.

21514421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21514421 is an equidigital number, since it uses as much as digits as its factorization.

21514421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 320, while the sum is 20.

The square root of 21514421 is about 4638.3640434964. The cubic root of 21514421 is about 278.1270445669.

Adding to 21514421 its reverse (12441512), we get a palindrome (33955933).

The spelling of 21514421 in words is "twenty-one million, five hundred fourteen thousand, four hundred twenty-one".