21425398 has 4 divisors (see below), whose sum is σ = 32138100. Its totient is φ = 10712698.

The previous prime is 21425387. The next prime is 21425399. The reversal of 21425398 is 89352412.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5356348 + ... + 5356351.

It is an arithmetic number, because the mean of its divisors is an integer number (8034525).

Almost surely, 2^21425398 is an apocalyptic number.

21425398 is a deficient number, since it is larger than the sum of its proper divisors (10712702).

21425398 is a wasteful number, since it uses less digits than its factorization.

21425398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10712701.

The product of its digits is 17280, while the sum is 34.

The square root of 21425398 is about 4628.7577167097. The cubic root of 21425398 is about 277.7429001662.

The spelling of 21425398 in words is "twenty-one million, four hundred twenty-five thousand, three hundred ninety-eight".