21310398 has 16 divisors (see below), whose sum is σ = 47356560. Its totient is φ = 7103448.

The previous prime is 21310337. The next prime is 21310417. The reversal of 21310398 is 89301312.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 7 ways as a sum of consecutive naturals, for example, 197265 + ... + 197372.

It is an arithmetic number, because the mean of its divisors is an integer number (2959785).

Almost surely, 2^21310398 is an apocalyptic number.

21310398 is an abundant number, since it is smaller than the sum of its proper divisors (26046162).

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

21310398 is a wasteful number, since it uses less digits than its factorization.

21310398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394648 (or 394642 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21310398 is about 4616.3186631774. The cubic root of 21310398 is about 277.2450836513.

The spelling of 21310398 in words is "twenty-one million, three hundred ten thousand, three hundred ninety-eight".