21367944 has 96 divisors (see below), whose sum is σ = 64111320. Its totient is φ = 6386688.

The previous prime is 21367933. The next prime is 21367979. The reversal of 21367944 is 44976312.

It can be written as a sum of positive squares in 4 ways, for example, as 13176900 + 8191044 = 3630^2 + 2862^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (36288) is a multiple of the sum of its prime divisors (672).

It is a junction number, because it is equal to n+sod(n) for n = 21367899 and 21367908.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34324 + ... + 34940.

Almost surely, 2^21367944 is an apocalyptic number.

21367944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21367944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32055660).

21367944 is an abundant number, since it is smaller than the sum of its proper divisors (42743376).

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

21367944 is a wasteful number, since it uses less digits than its factorization.

21367944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679 (or 672 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21367944 is about 4622.5473496764. The cubic root of 21367944 is about 277.4944143020.

The spelling of 21367944 in words is "twenty-one million, three hundred sixty-seven thousand, nine hundred forty-four".