21508119 has 16 divisors (see below), whose sum is σ = 32032000. Its totient is φ = 14263128.

The previous prime is 21508117. The next prime is 21508121. The reversal of 21508119 is 91180512.

It is an interprime number because it is at equal distance from previous prime (21508117) and next prime (21508121).

It is not a de Polignac number, because 21508119 - 2¹ = 21508117 is a prime.

It is a super-2 number, since 2×21508119² = 925198365836322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21508092 and 21508101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21508117) 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, 3372 + ... + 7374.

It is an arithmetic number, because the mean of its divisors is an integer number (2002000).

Almost surely, 2^21508119 is an apocalyptic number.

21508119 is a deficient number, since it is larger than the sum of its proper divisors (10523881).

21508119 is a wasteful number, since it uses less digits than its factorization.

21508119 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4211 (or 4205 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 21508119 is about 4637.6846593963. The cubic root of 21508119 is about 278.0998856084.

The spelling of 21508119 in words is "twenty-one million, five hundred eight thousand, one hundred nineteen".