21393190 has 32 divisors (see below), whose sum is σ = 47396160. Its totient is φ = 6770304.

The previous prime is 21393187. The next prime is 21393233. The reversal of 21393190 is 9139312.

It is a super-2 number, since 2×21393190² = 915337156752200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10845 + ... + 12664.

It is an arithmetic number, because the mean of its divisors is an integer number (1481130).

Almost surely, 2^21393190 is an apocalyptic number.

21393190 is an abundant number, since it is smaller than the sum of its proper divisors (26002970).

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

21393190 is a wasteful number, since it uses less digits than its factorization.

21393190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23536.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 21393190 is about 4625.2772889850. The cubic root of 21393190 is about 277.6036568629.

It can be divided in two parts, 2139 and 3190, that added together give a square (5329 = 73²).

The spelling of 21393190 in words is "twenty-one million, three hundred ninety-three thousand, one hundred ninety".