21193690 has 16 divisors (see below), whose sum is σ = 43598592. Its totient is φ = 7266384.

The previous prime is 21193651. The next prime is 21193691. The reversal of 21193690 is 9639112.

It is a super-2 number, since 2×21193690² = 898344991632200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21193691) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 151314 + ... + 151453.

It is an arithmetic number, because the mean of its divisors is an integer number (2724912).

Almost surely, 2^21193690 is an apocalyptic number.

21193690 is an abundant number, since it is smaller than the sum of its proper divisors (22404902).

21193690 is a wasteful number, since it uses less digits than its factorization.

21193690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302781.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 21193690 is about 4603.6605000803. The cubic root of 21193690 is about 276.7380390370.

The spelling of 21193690 in words is "twenty-one million, one hundred ninety-three thousand, six hundred ninety".