21949460 has 24 divisors (see below), whose sum is σ = 49640136. Its totient is φ = 8104320.

The previous prime is 21949453. The next prime is 21949463. The reversal of 21949460 is 6494912.

It can be written as a sum of positive squares in 4 ways, for example, as 3579664 + 18369796 = 1892^2 + 4286^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21949460.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21949463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41951 + ... + 42470.

It is an arithmetic number, because the mean of its divisors is an integer number (2068339).

Almost surely, 2^21949460 is an apocalyptic number.

21949460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21949460 is an abundant number, since it is smaller than the sum of its proper divisors (27690676).

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

21949460 is a wasteful number, since it uses less digits than its factorization.

21949460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84443 (or 84441 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 21949460 is about 4685.0250799756. The cubic root of 21949460 is about 279.9892002637.

The spelling of 21949460 in words is "twenty-one million, nine hundred forty-nine thousand, four hundred sixty".