21140946 has 64 divisors (see below), whose sum is σ = 49443840. Its totient is φ = 6687360.

The previous prime is 21140921. The next prime is 21140957. The reversal of 21140946 is 64904112.

21140946 is a `hidden beast` number, since 211 + 409 + 46 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 122116 + ... + 122288.

It is an arithmetic number, because the mean of its divisors is an integer number (772560).

Almost surely, 2^21140946 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21140946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24721920).

21140946 is an abundant number, since it is smaller than the sum of its proper divisors (28302894).

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

21140946 is a wasteful number, since it uses less digits than its factorization.

21140946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21140946 is about 4597.9284465942. The cubic root of 21140946 is about 276.5082788849.

The spelling of 21140946 in words is "twenty-one million, one hundred forty thousand, nine hundred forty-six".