21503219 has 2 divisors, whose sum is σ = 21503220. Its totient is φ = 21503218.

The previous prime is 21503197. The next prime is 21503227. The reversal of 21503219 is 91230512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21503219 - 2¹² = 21499123 is a prime.

It is a super-2 number, since 2×21503219² = 924776854723922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21503194 and 21503203.

It is not a weakly prime, because it can be changed into another prime (21503719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751609 + 10751610.

It is an arithmetic number, because the mean of its divisors is an integer number (10751610).

Almost surely, 2^21503219 is an apocalyptic number.

21503219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21503219 is an equidigital number, since it uses as much as digits as its factorization.

21503219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 21503219 is about 4637.1563484532. The cubic root of 21503219 is about 278.0787650115.

The spelling of 21503219 in words is "twenty-one million, five hundred three thousand, two hundred nineteen".