21910828 has 12 divisors (see below), whose sum is σ = 38406592. Its totient is φ = 10937520.

The previous prime is 21910799. The next prime is 21910829. The reversal of 21910828 is 82801912.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21910828.

It is not an unprimeable number, because it can be changed into a prime (21910829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1500 + ... + 6787.

Almost surely, 2^21910828 is an apocalyptic number.

It is an amenable number.

21910828 is a deficient number, since it is larger than the sum of its proper divisors (16495764).

21910828 is a wasteful number, since it uses less digits than its factorization.

21910828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8952 (or 8950 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 21910828 is about 4680.9003407464. The cubic root of 21910828 is about 279.8248394266.

The spelling of 21910828 in words is "twenty-one million, nine hundred ten thousand, eight hundred twenty-eight".