21902946 has 64 divisors (see below), whose sum is σ = 51045120. Its totient is φ = 6209280.

The previous prime is 21902941. The next prime is 21902963. The reversal of 21902946 is 64920912.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21902941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51816 + ... + 52236.

It is an arithmetic number, because the mean of its divisors is an integer number (797580).

Almost surely, 2^21902946 is an apocalyptic number.

21902946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21902946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25522560).

21902946 is an abundant number, since it is smaller than the sum of its proper divisors (29142174).

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

21902946 is a wasteful number, since it uses less digits than its factorization.

21902946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 21902946 is about 4680.0583329698. The cubic root of 21902946 is about 279.7912815299.

The spelling of 21902946 in words is "twenty-one million, nine hundred two thousand, nine hundred forty-six".