21193722 has 48 divisors (see below), whose sum is σ = 51835680. Its totient is φ = 6199200.

The previous prime is 21193691. The next prime is 21193727. The reversal of 21193722 is 22739112.

It is not an unprimeable number, because it can be changed into a prime (21193727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3897 + ... + 7587.

It is an arithmetic number, because the mean of its divisors is an integer number (1079910).

Almost surely, 2^21193722 is an apocalyptic number.

21193722 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21193722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25917840).

21193722 is an abundant number, since it is smaller than the sum of its proper divisors (30641958).

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

21193722 is a wasteful number, since it uses less digits than its factorization.

21193722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3739 (or 3736 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21193722 is about 4603.6639755742. The cubic root of 21193722 is about 276.7381783177.

The spelling of 21193722 in words is "twenty-one million, one hundred ninety-three thousand, seven hundred twenty-two".