21225398 has 4 divisors (see below), whose sum is σ = 31838100. Its totient is φ = 10612698.

The previous prime is 21225397. The next prime is 21225403. The reversal of 21225398 is 89352212.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5306348 + ... + 5306351.

It is an arithmetic number, because the mean of its divisors is an integer number (7959525).

Almost surely, 2^21225398 is an apocalyptic number.

21225398 is a deficient number, since it is larger than the sum of its proper divisors (10612702).

21225398 is a wasteful number, since it uses less digits than its factorization.

21225398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10612701.

The product of its digits is 8640, while the sum is 32.

The square root of 21225398 is about 4607.1029942904. The cubic root of 21225398 is about 276.8759800525.

The spelling of 21225398 in words is "twenty-one million, two hundred twenty-five thousand, three hundred ninety-eight".