21740798 has 4 divisors (see below), whose sum is σ = 32611200. Its totient is φ = 10870398.

The previous prime is 21740791. The next prime is 21740801. The reversal of 21740798 is 89704712.

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 (21740791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5435198 + ... + 5435201.

It is an arithmetic number, because the mean of its divisors is an integer number (8152800).

Almost surely, 2^21740798 is an apocalyptic number.

21740798 is a deficient number, since it is larger than the sum of its proper divisors (10870402).

21740798 is a wasteful number, since it uses less digits than its factorization.

21740798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10870401.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 21740798 is about 4662.7028642194. The cubic root of 21740798 is about 279.0991370138.

The spelling of 21740798 in words is "twenty-one million, seven hundred forty thousand, seven hundred ninety-eight".