21398097 has 8 divisors (see below), whose sum is σ = 32606656. Its totient is φ = 12227472.

The previous prime is 21398081. The next prime is 21398101. The reversal of 21398097 is 79089312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21398097 - 2⁴ = 21398081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21398017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 509458 + ... + 509499.

It is an arithmetic number, because the mean of its divisors is an integer number (4075832).

Almost surely, 2^21398097 is an apocalyptic number.

It is an amenable number.

21398097 is a deficient number, since it is larger than the sum of its proper divisors (11208559).

21398097 is a wasteful number, since it uses less digits than its factorization.

21398097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018967.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 21398097 is about 4625.8077132540. The cubic root of 21398097 is about 277.6248800809.

The spelling of 21398097 in words is "twenty-one million, three hundred ninety-eight thousand, ninety-seven".