21530194 has 32 divisors (see below), whose sum is σ = 39747456. Its totient is φ = 8536320.

The previous prime is 21530161. The next prime is 21530227. The reversal of 21530194 is 49103512.

It is an interprime number because it is at equal distance from previous prime (21530161) and next prime (21530227).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13777 + ... + 15259.

It is an arithmetic number, because the mean of its divisors is an integer number (1242108).

Almost surely, 2^21530194 is an apocalyptic number.

21530194 is a deficient number, since it is larger than the sum of its proper divisors (18217262).

21530194 is a wasteful number, since it uses less digits than its factorization.

21530194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1570.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21530194 is about 4640.0640081792. The cubic root of 21530194 is about 278.1949962948.

The spelling of 21530194 in words is "twenty-one million, five hundred thirty thousand, one hundred ninety-four".