21628298 has 4 divisors (see below), whose sum is σ = 32442450. Its totient is φ = 10814148.

The previous prime is 21628283. The next prime is 21628339. The reversal of 21628298 is 89282612.

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

It can be written as a sum of positive squares in only one way, i.e., 20367169 + 1261129 = 4513^2 + 1123^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5407073 + ... + 5407076.

Almost surely, 2^21628298 is an apocalyptic number.

21628298 is a deficient number, since it is larger than the sum of its proper divisors (10814152).

21628298 is a wasteful number, since it uses less digits than its factorization.

21628298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10814151.

The product of its digits is 27648, while the sum is 38.

The square root of 21628298 is about 4650.6233990724. The cubic root of 21628298 is about 278.6168951680.

The spelling of 21628298 in words is "twenty-one million, six hundred twenty-eight thousand, two hundred ninety-eight".