21956946 has 32 divisors (see below), whose sum is σ = 48817728. Its totient is φ = 6527040.

The previous prime is 21956941. The next prime is 21956971. The reversal of 21956946 is 64965912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21956898 and 21956907.

It is not an unprimeable number, because it can be changed into a prime (21956941) 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 15 ways as a sum of consecutive naturals, for example, 360 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (1525554).

Almost surely, 2^21956946 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21956946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24408864).

21956946 is an abundant number, since it is smaller than the sum of its proper divisors (26860782).

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

21956946 is a wasteful number, since it uses less digits than its factorization.

21956946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6346.

The product of its digits is 116640, while the sum is 42.

The square root of 21956946 is about 4685.8239403546. The cubic root of 21956946 is about 280.0210273324.

The spelling of 21956946 in words is "twenty-one million, nine hundred fifty-six thousand, nine hundred forty-six".