209621019 has 8 divisors (see below), whose sum is σ = 289132560. Its totient is φ = 134928416.

The previous prime is 209621017. The next prime is 209621051. The reversal of 209621019 is 910126902.

It is a happy number.

209621019 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 209621019 - 2¹ = 209621017 is a prime.

It is a super-2 number, since 2×209621019² = 87881943213196722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (209621017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1204632 + ... + 1204805.

It is an arithmetic number, because the mean of its divisors is an integer number (36141570).

Almost surely, 2^209621019 is an apocalyptic number.

209621019 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

209621019 is a deficient number, since it is larger than the sum of its proper divisors (79511541).

209621019 is a wasteful number, since it uses less digits than its factorization.

209621019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409469.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 209621019 is about 14478.2947545628. The cubic root of 209621019 is about 594.0344190964.

The spelling of 209621019 in words is "two hundred nine million, six hundred twenty-one thousand, nineteen".