21498091 has 2 divisors, whose sum is σ = 21498092. Its totient is φ = 21498090.

The previous prime is 21498083. The next prime is 21498107. The reversal of 21498091 is 19089412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21498091 - 2³ = 21498083 is a prime.

It is not a weakly prime, because it can be changed into another prime (21498041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10749045 + 10749046.

It is an arithmetic number, because the mean of its divisors is an integer number (10749046).

Almost surely, 2^21498091 is an apocalyptic number.

21498091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21498091 is an equidigital number, since it uses as much as digits as its factorization.

21498091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 21498091 is about 4636.6033904142. The cubic root of 21498091 is about 278.0566582240.

The spelling of 21498091 in words is "twenty-one million, four hundred ninety-eight thousand, ninety-one".