21905298 has 12 divisors (see below), whose sum is σ = 47461518. Its totient is φ = 7301760.

The previous prime is 21905297. The next prime is 21905321. The reversal of 21905298 is 89250912.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 6671889 = 3903^2 + 2583^2 .

It is not an unprimeable number, because it can be changed into a prime (21905291) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 608463 + ... + 608498.

Almost surely, 2^21905298 is an apocalyptic number.

21905298 is an abundant number, since it is smaller than the sum of its proper divisors (25556220).

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

21905298 is a wasteful number, since it uses less digits than its factorization.

21905298 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216969 (or 1216966 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 21905298 is about 4680.3096051437. The cubic root of 21905298 is about 279.8012960966.

The spelling of 21905298 in words is "twenty-one million, nine hundred five thousand, two hundred ninety-eight".