21365042 has 8 divisors (see below), whose sum is σ = 32652396. Its totient is φ = 10480912.

The previous prime is 21365041. The next prime is 21365077. The reversal of 21365042 is 24056312.

It can be written as a sum of positive squares in 2 ways, for example, as 19545241 + 1819801 = 4421^2 + 1349^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21364999 and 21365017.

It is not an unprimeable number, because it can be changed into a prime (21365041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100673 + ... + 100884.

Almost surely, 2^21365042 is an apocalyptic number.

21365042 is a deficient number, since it is larger than the sum of its proper divisors (11287354).

21365042 is a wasteful number, since it uses less digits than its factorization.

21365042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201612.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21365042 is about 4622.2334428283. The cubic root of 21365042 is about 277.4818514766.

The spelling of 21365042 in words is "twenty-one million, three hundred sixty-five thousand, forty-two".