21520194 has 16 divisors (see below), whose sum is σ = 43102368. Its totient is φ = 7163072.

The previous prime is 21520193. The next prime is 21520207. The reversal of 21520194 is 49102512.

It is not an unprimeable number, because it can be changed into a prime (21520193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2794 + ... + 7130.

It is an arithmetic number, because the mean of its divisors is an integer number (2693898).

Almost surely, 2^21520194 is an apocalyptic number.

21520194 is an abundant number, since it is smaller than the sum of its proper divisors (21582174).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21520194 is a wasteful number, since it uses less digits than its factorization.

21520194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5169.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21520194 is about 4638.9863116849. The cubic root of 21520194 is about 278.1519191047.

The spelling of 21520194 in words is "twenty-one million, five hundred twenty thousand, one hundred ninety-four".