21323019 has 8 divisors (see below), whose sum is σ = 28712592. Its totient is φ = 14074400.

The previous prime is 21323011. The next prime is 21323021. The reversal of 21323019 is 91032312.

It is a happy number.

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 21323019 - 2³ = 21323011 is a prime.

It is a super-2 number, since 2×21323019² = 909342278548722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21322986 and 21323004.

It is not an unprimeable number, because it can be changed into a prime (21323011) 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, 34884 + ... + 35489.

It is an arithmetic number, because the mean of its divisors is an integer number (3589074).

Almost surely, 2^21323019 is an apocalyptic number.

21323019 is a deficient number, since it is larger than the sum of its proper divisors (7389573).

21323019 is a wasteful number, since it uses less digits than its factorization.

21323019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70477.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 21323019 is about 4617.6854591884. The cubic root of 21323019 is about 277.2998052892.

It can be divided in two parts, 2132 and 3019, that added together give a triangular number (5151 = T₁₀₁).

The spelling of 21323019 in words is "twenty-one million, three hundred twenty-three thousand, nineteen".