21290190 has 16 divisors (see below), whose sum is σ = 51096528. Its totient is φ = 5677376.

The previous prime is 21290189. The next prime is 21290219. The reversal of 21290190 is 9109212.

It is a super-2 number, since 2×21290190² = 906544380472200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21290190.

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 7 ways as a sum of consecutive naturals, for example, 354807 + ... + 354866.

It is an arithmetic number, because the mean of its divisors is an integer number (3193533).

Almost surely, 2^21290190 is an apocalyptic number.

21290190 is an abundant number, since it is smaller than the sum of its proper divisors (29806338).

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

21290190 is a wasteful number, since it uses less digits than its factorization.

21290190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709683.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 21290190 is about 4614.1293870025. The cubic root of 21290190 is about 277.1574215860.

The spelling of 21290190 in words is "twenty-one million, two hundred ninety thousand, one hundred ninety".