21494460 has 96 divisors (see below), whose sum is σ = 68668992. Its totient is φ = 4976640.

The previous prime is 21494449. The next prime is 21494461. The reversal of 21494460 is 6449412.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21494461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12450 + ... + 14070.

It is an arithmetic number, because the mean of its divisors is an integer number (715302).

Almost surely, 2^21494460 is an apocalyptic number.

21494460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21494460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34334496).

21494460 is an abundant number, since it is smaller than the sum of its proper divisors (47174532).

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

21494460 is a wasteful number, since it uses less digits than its factorization.

21494460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1663 (or 1661 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 21494460 is about 4636.2118156961. The cubic root of 21494460 is about 278.0410028716.

The spelling of 21494460 in words is "twenty-one million, four hundred ninety-four thousand, four hundred sixty".