21968370 has 96 divisors (see below), whose sum is σ = 62337600. Its totient is φ = 5346432.

The previous prime is 21968363. The next prime is 21968371. The reversal of 21968370 is 7386912.

It is not an unprimeable number, because it can be changed into a prime (21968371) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 49369 + ... + 49811.

It is an arithmetic number, because the mean of its divisors is an integer number (649350).

Almost surely, 2^21968370 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21968370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31168800).

21968370 is an abundant number, since it is smaller than the sum of its proper divisors (40369230).

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

21968370 is a wasteful number, since it uses less digits than its factorization.

21968370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21968370 is about 4687.0427777011. The cubic root of 21968370 is about 280.0695830466.

The spelling of 21968370 in words is "twenty-one million, nine hundred sixty-eight thousand, three hundred seventy".