21349019 has 2 divisors, whose sum is σ = 21349020. Its totient is φ = 21349018.

The previous prime is 21349007. The next prime is 21349033. The reversal of 21349019 is 91094312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21349019 is a prime.

It is a super-3 number, since 3×21349019³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 21348982 and 21349000.

It is not a weakly prime, because it can be changed into another prime (21349079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10674509 + 10674510.

It is an arithmetic number, because the mean of its divisors is an integer number (10674510).

Almost surely, 2^21349019 is an apocalyptic number.

21349019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21349019 is an equidigital number, since it uses as much as digits as its factorization.

21349019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 21349019 is about 4620.4998647333. The cubic root of 21349019 is about 277.4124670488.

The spelling of 21349019 in words is "twenty-one million, three hundred forty-nine thousand, nineteen".