21620019 has 8 divisors (see below), whose sum is σ = 29315520. Its totient is φ = 14168936.

The previous prime is 21620017. The next prime is 21620021. The reversal of 21620019 is 91002612.

It is an interprime number because it is at equal distance from previous prime (21620017) and next prime (21620021).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21620019 - 2¹ = 21620017 is a prime.

It is a super-2 number, since 2×21620019² = 934850443120722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21619977 and 21620004.

It is not an unprimeable number, because it can be changed into a prime (21620017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60897 + ... + 61250.

It is an arithmetic number, because the mean of its divisors is an integer number (3664440).

Almost surely, 2^21620019 is an apocalyptic number.

21620019 is a deficient number, since it is larger than the sum of its proper divisors (7695501).

21620019 is a wasteful number, since it uses less digits than its factorization.

21620019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122209.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 21620019 is about 4649.7332181535. The cubic root of 21620019 is about 278.5813404569.

The spelling of 21620019 in words is "twenty-one million, six hundred twenty thousand, nineteen".