21320198 has 4 divisors (see below), whose sum is σ = 31980300. Its totient is φ = 10660098.

The previous prime is 21320197. The next prime is 21320203. The reversal of 21320198 is 89102312.

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 (21320197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5330048 + ... + 5330051.

It is an arithmetic number, because the mean of its divisors is an integer number (7995075).

Almost surely, 2^21320198 is an apocalyptic number.

21320198 is a deficient number, since it is larger than the sum of its proper divisors (10660102).

21320198 is a wasteful number, since it uses less digits than its factorization.

21320198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10660101.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21320198 is about 4617.3799930263. The cubic root of 21320198 is about 277.2875759820.

The spelling of 21320198 in words is "twenty-one million, three hundred twenty thousand, one hundred ninety-eight".