21294940 has 24 divisors (see below), whose sum is σ = 44840880. Its totient is φ = 8494848.

The previous prime is 21294937. The next prime is 21294989. The reversal of 21294940 is 4949212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7431 + ... + 9889.

It is an arithmetic number, because the mean of its divisors is an integer number (1868370).

Almost surely, 2^21294940 is an apocalyptic number.

21294940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21294940 is an abundant number, since it is smaller than the sum of its proper divisors (23545940).

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

21294940 is a wasteful number, since it uses less digits than its factorization.

21294940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2901 (or 2899 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21294940 is about 4614.6440816167. The cubic root of 21294940 is about 277.1780320152.

The spelling of 21294940 in words is "twenty-one million, two hundred ninety-four thousand, nine hundred forty".