21964198 has 4 divisors (see below), whose sum is σ = 32946300. Its totient is φ = 10982098.

The previous prime is 21964193. The next prime is 21964219. The reversal of 21964198 is 89146912.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 21964198.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21964193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5491048 + ... + 5491051.

It is an arithmetic number, because the mean of its divisors is an integer number (8236575).

Almost surely, 2^21964198 is an apocalyptic number.

21964198 is a deficient number, since it is larger than the sum of its proper divisors (10982102).

21964198 is a wasteful number, since it uses less digits than its factorization.

21964198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10982101.

The product of its digits is 31104, while the sum is 40.

The square root of 21964198 is about 4686.5976998245. The cubic root of 21964198 is about 280.0518526418.

The spelling of 21964198 in words is "twenty-one million, nine hundred sixty-four thousand, one hundred ninety-eight".