21961746 has 16 divisors (see below), whose sum is σ = 48804000. Its totient is φ = 7320564.

The previous prime is 21961741. The next prime is 21961781. The reversal of 21961746 is 64716912.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21961746.

It is not an unprimeable number, because it can be changed into a prime (21961741) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 203296 + ... + 203403.

It is an arithmetic number, because the mean of its divisors is an integer number (3050250).

Almost surely, 2^21961746 is an apocalyptic number.

21961746 is an abundant number, since it is smaller than the sum of its proper divisors (26842254).

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

21961746 is a wasteful number, since it uses less digits than its factorization.

21961746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406710 (or 406704 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 21961746 is about 4686.3360955015. The cubic root of 21961746 is about 280.0414309441.

The spelling of 21961746 in words is "twenty-one million, nine hundred sixty-one thousand, seven hundred forty-six".