21673036 has 36 divisors (see below), whose sum is σ = 47652304. Its totient is φ = 8442720.

The previous prime is 21673031. The next prime is 21673039. The reversal of 21673036 is 63037612.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 21672995 and 21673013.

It is not an unprimeable number, because it can be changed into a prime (21673031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190 + ... + 6586.

Almost surely, 2^21673036 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21673036, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23826152).

21673036 is an abundant number, since it is smaller than the sum of its proper divisors (25979268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21673036 is a wasteful number, since it uses less digits than its factorization.

21673036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6430 (or 6417 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 21673036 is about 4655.4308071327. The cubic root of 21673036 is about 278.8088686355.

The spelling of 21673036 in words is "twenty-one million, six hundred seventy-three thousand, thirty-six".