21340398 has 8 divisors (see below), whose sum is σ = 42680808. Its totient is φ = 7113464.

The previous prime is 21340387. The next prime is 21340409. The reversal of 21340398 is 89304312.

It is an interprime number because it is at equal distance from previous prime (21340387) and next prime (21340409).

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

21340398 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1778361 + ... + 1778372.

It is an arithmetic number, because the mean of its divisors is an integer number (5335101).

Almost surely, 2^21340398 is an apocalyptic number.

21340398 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21340398 is a wasteful number, since it uses less digits than its factorization.

21340398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3556738.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21340398 is about 4619.5668628130. The cubic root of 21340398 is about 277.3751211507.

The spelling of 21340398 in words is "twenty-one million, three hundred forty thousand, three hundred ninety-eight".