21910842 has 12 divisors (see below), whose sum is σ = 47473530. Its totient is φ = 7303608.

The previous prime is 21910829. The next prime is 21910843. The reversal of 21910842 is 24801912.

It can be written as a sum of positive squares in only one way, i.e., 19633761 + 2277081 = 4431^2 + 1509^2 .

It is not an unprimeable number, because it can be changed into a prime (21910843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 608617 + ... + 608652.

Almost surely, 2^21910842 is an apocalyptic number.

21910842 is an abundant number, since it is smaller than the sum of its proper divisors (25562688).

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

21910842 is a wasteful number, since it uses less digits than its factorization.

21910842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217277 (or 1217274 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21910842 is about 4680.9018361850. The cubic root of 21910842 is about 279.8248990250.

The spelling of 21910842 in words is "twenty-one million, nine hundred ten thousand, eight hundred forty-two".