21910194 has 12 divisors (see below), whose sum is σ = 47472126. Its totient is φ = 7303392.

The previous prime is 21910193. The next prime is 21910201. The reversal of 21910194 is 49101912.

It can be written as a sum of positive squares in only one way, i.e., 14538969 + 7371225 = 3813^2 + 2715^2 .

It is a super-2 number, since 2×21910194² = 960113202235272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21910193) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 608599 + ... + 608634.

Almost surely, 2^21910194 is an apocalyptic number.

21910194 is an abundant number, since it is smaller than the sum of its proper divisors (25561932).

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

21910194 is a wasteful number, since it uses less digits than its factorization.

21910194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1217241 (or 1217238 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 21910194 is about 4680.8326182422. The cubic root of 21910194 is about 279.8221404466.

The spelling of 21910194 in words is "twenty-one million, nine hundred ten thousand, one hundred ninety-four".